i have found instances where i took a different path than philosophy early for the national collega for ex, also forgoing on loosing the time to build it like the great library and not go for tradition early, and rather expand fast and really try to get lot of poppulation fast to make up for the shortfall of not having the national collega by rapid expansion and building the national college later. there are ways to make up for what you misss per turn by notbuilding the national college early. Im trying strategy's with rapid expansion and civs of 8 city's rather than 4 using liberty and i have some progress and succes.
One way is to consider how fast you can grow people to make the national college more meaningfull, afaik it gives a bonus to research all over the civilization thus while it might be build at some later point, if one at that later point is at a significantly higher poppulation with more city's than the one that waited and took time/effort to build the national college first, then that might make up for the shortfall among other things. (just having grown more in general by then)
This might imply aresearch more oriented towards quick expansion and growth and very bend on getting quite a few settlers and workers very fast.
There are other ways to get more science by expanding. there is the messenger of the gods pantheon that gives +2 science for every city connection. The maya's have a shrine that produces 2 faith and 2 science which might prompt one to consider having more early city's with one of these in it.
Then there is the koreans, maybe with them rather you might like to beeline for currency most of all while expanding, and try to get techs asap that gives you specialists buildings as every specialist gives an added 2 science. it might allow the koreans to expand and take a different research path leading rather to wonders like the hanging gardens and Petra.
I was trying out a strategy earlier with the maya's with large expansion. otherwise usually the strategy was 4 city's and tradition and that is a quite potent strategy, but different paths would indeed be nice. Though while its so thart early one by keeping it small and concentrating poppulation in a few city's will allow you to build the national college soon and grow fast with tradition, while hapyness is not easy to get early on by the late game one does have significantly more of it usually and that imply's by the late game you better have like 8 city's or more with the extra poppulation for more science, so youre using all the happyness you got. Afcourse, if you choose not to expand much early on youre less likely to grab a lot of luxury's later than if you did so early to the size of 8 city's, or youll need to war a bit over those extra city's.
otoh, could one make up for the fact that it's almost impossible to build the national college early when aiming for rapid expansion? Thus with the maya the strategy was to get a lot of city's quick rather trough liberty and very beelining strait for that free settler and the 50% reduction on building it in culture, and then hard building settlers to the point that i had like 8 city's all near or even settled on luxury's and with just enough workers around to work a few luxury's to plantations,quary's or mine's while i was setlling city's. the first tech was still pottery but after that it was calender and then mining, then animal husbandry and trapping, no need for writing as the capital stayed at size 5 while building settlers and every city was to build that special Maya shrine asap afcourse, then a monument, library was only interresting for larger city's. Messenger of the gods as religion would be chosen and city connections would come soon. Another consideration was that being larger might allow the civ to catch more trade routes from other civs and thus gaining some added research there from being big, caravanseray's would be build in the hope that would pull more research bringing trade to the civ. The end point being that you get big early on, if you can manage it withought falling behind then you will outtech youre opponents easily later on because of more poppulation later, more university's with specialists etc.
A capital city size 6 with a national college and a library produces 18 research iirc? A mayan capital size 4 + its shrine makes 9 research, then you would need like 2 added city's size 2 + shrine's to about make up with that early on, liberty will give you a settler soon if you beeline for it and harbuilding one after youve unlocked that policy doesn't take to much time, the maya's shrine's are cheap and so are their early archer units so you might actually get all that before you could have build the national college.
A capitol size 10 + 3 added city's size 6 all having a library and with the national college around will produce roughly 67 research. If the maya's have 8 city's with a shrine in it then that gives them 16 research, if by then all city's are connected and imbued by the pantheon belief then thats another 14 research and with the +3 research bonus of the capital that makes a total of 33 research not counting poppulation. Withought library's then the maya would need a poppulation of 34 total to make as much research as the 4 city's with size 10-6-6-6 respectivly combvined, or 28 poppulation total there. for the the added 4 city's will produce an added 12 unhapiness, so the maya's here need to find an added 18 happyness to make up for poppulation/city's. When the maya's should have build library's in those 8 city's, then it only needs 22 population they need to make as much as the 4 city's, still with a 12 unhapiness by number of city's, then the maya's only need to find 1 extra luxury to make up for the unhapyness and make as much research with their 8 city's of an average size 3 as the 4 tall city's strategy. When the national college then gets eventually build, the maya's are bigger and stronger and will make another 50% more research or something like a 100 beakers, not bad if you can do all that before you get to education, and essentially youre 8 Maya city's need only a cheap shrine, a library and some minimal poppulation for the research and making the roads profitablme. (you can avoid growth in favor of production here)
probably the maya's should build there many city's against mountains, if youre going for the maximum research output trough loads of poppulation in many city's when you have more hapyness later, then the added 50% from having observatory's everywhere will jsut make so much more inpact.
That said, expanding to 8 city's in time with decent luxury's around while there other civs around is not always easy, ive tested this strategy on emperor and i grew faster than the ai but in that game i ran out of usefull near land to expand beyond 4 city's.