Ok so can you tell me again, what are all the reasons why you would ever want to disconnect your own resources? You mentioned this above, also, in response to the question about planting cities on top of a resource.
Thanks
1. You can build cheaper units and then upgrade them. Doing this ends up costing less than cash-rushing the units would. Also, so long as you have enough cash, it'll produce more advanced units faster than if you had not cash-rushed those units. For example, if you want cavalry quickly and have some cash to spare, you could either
A. just let the cavalry complete regularly and micromanage, which takes a few turns no matter what you do,
B. buy a worker, and then swap to a cavalry which costs you (80+(4*70))=360 gold with no shields in the box,
C. with say 30 shields in the box, you would pay (50*4)=200 gold to complete the cavalry via cash-rushing... note that once you have a shield in the box you pay 4 gold per shield when cash-rushing (no exceptions)...
D. put out a horseman with the saltpeter and/or iron disconnected (if you learn a tech during the inter-turn, or you'll have to wait to upgrade). Then reconnect the saltpeter. Then zoom to the city, and you can pay 50 shields worth in upgrading. Since you upgrade at 3 gold per shield, without Leo's, you'll pay 150 gold for the upgrade. So, you save 50 gold
for each horseman you upgrade over cash-rushing it. I repeat, that's 50 gold saved
without Leo's. With Leo's you pay 1.5 gold per shield in upgrades. So, if you upgrade from a horseman to a cavalry you pay (1.5*50)=75 gold. So, you save 125 gold
for each horseman you upgrade over cash-rushing it if you have Leo's.
Of course, upgrading to knights or swordsmen/medieval infantry of some type might come as a better example here, but I just put that forth as an example.
2. If you disconnect your resource, you can then trade for any extra resources the AIs have. Combine that with a disconnect of your capital after trading for those resources with the AIs, and you can obtain techs, gold, gpt (via the lump sums you have... see the screenshots above), workers, and a declaration of war from the AI.
I'll also note that there do exist other ways to obtain cash on higher levels especially, or later on in lower level games. You can sell techs for gpt. You can also pay gpt to the AIs for their lump sums (and then try to get them to declare war on one way or another to get your gpt back). And, of course, you can try shutting off research at some point/doing minimal research at some point.
If anyone reading this hasn't tried to see how much faster you can get train a powerful army by disconnecting your own resources (mostly iron/saltpeter... there's no need to disconnect horses, and I haven't done any disconnects to upgrade from tanks to modern armor), and then reconnecting them and upgrading, I would highly recommend giving this a go sometime on a larger map size. It might take more work, but you won't realize how powerful it can work until you've tried it at least once.