you tend to hold territories better when you bleed the enemy down quickly. Tanks are not very cost efficient when one can use inf and air to kill them. Yes they defend well, but are be killed very easily. You never really need to defend any territory since your aim is to bleed the enemy down. For china, u can have a very efficient stack move closer and closer, and eventually, the air and your stack wipes them out. If they try to counter, they will not likely have good counter attacking odds, and u cause him to divide/lose some units that he really can’t replace as well as you. Same case with India. Your india kill is all about the amount of fodder u can throw at it since your planes can very easily get in range. I very rarely buy 3 tanks a turn out of mainland factories as Japan anymore since I cant have nearly the same effect, buy spending 12 instead of 18 for 3 mechs.