If u read my whole suggestion then u might understand why I suggested this. I said that siege units should be more resistant to ranged attacks, this might make them too powerful thats why nerfing their attack against cities.
I have no problem with making cats and trebs (and maybe cannon?)more resilient to ranged attacks from cities. But I don't see that this needs to weaken their anti-city attack strength. If necessary they could have even more of the flavor they did in VEM, with slightly reduced ranged attack but further boosted bonus vs cities.
Artillery are a different kettle of fish because of their 3-tile range, and because they are relatively more effective vs units. I wouldn't try to balance all siege units based on the performance of artillery. Artillery could arguably be made slightly less effective vs cities.
I think siege units are already quite susceptible to cavalry, and I wouldn't want to make them more susceptible. And sitting 3 tiles away and shooting the city while everything else hides out of range is only going to work if the enemy doesn't have an army (otherwise they're going to be throwing melee/mounted units at your arty).
The main thing is the shared tech cost modifier.
It seems to me that the shared tech modifier isn't the main issue here, it is the fact that tech per-tech costs increase dramatically as we move rightwards. VEM also had global tech cost multiplier increases for each era on the belief that tech progress in vanilla was too fast. Are these not going to be added back for GEM?
[I agree that the shared tech cost modifier is important for inefficiency, but it isn't the main thing that prevents beelines from being overwhelming.]
I agree with this for later eras, but not the ancient era. I dislike ancient era conquest for two reasons:
Swords aren't ancient era (they're classical, no?). So I don't think this is very relevant.
My point isn't about ancient era rushes. It the situation where you get to the classical era, but aren't getting military techs. If you're focused solely on getting economy techs and building up wonders/economy infrastructure (libraries, etc) then you should get beaten up by the game who does a balanced build that includes horseback riding or iron working and brings some real military units to the fight. Ancient era units should not be able to fight off classical era units.
You shouldn't be able to go ~8-10 techs in without getting some real military techs unless you are very isolated, or are willing to take a big risk in terms of being vulnerable to invasion.
With spearmen; I think spearmen should be much more powerful than warriors. They don't necessarily need to be massively more powerful offensively, though they should still have a significant advantage, but they need to be much better overall units because of the 25% defense bonus. I don't think the attack bonus warrior vs spear needs to be 6 vs 11 like in G&K, but I think it should be much larger than 6 vs 7 or 8. And an offensive swarming strategy with hoplites or immortals should be possible, or those are really weak UUs.
6 strength warriors vs strength 10 spearman with +25% vs horse +25% defense should probably work fine. That 6 strength warrior fortified on rough terrain is going to hold up fairly well to a strength 10 spearman attacking it.
I'd also say that capturing another capital in the early game isn't that amazing, because you're getting a city that is probably a long way away and is going to be a puppet, with all the puppet penalties (which I assume will transfer from VEM to GEM). If you wanted to expand a lot, you'd almost certainly be better off building settlers than you would building spears.