The main thing that limits the units on the map is your ram amount. Is the lag manageable yes its not painful to the point that you cant play as I was doing fine when testing it that map was made for the 100M kill achiv as devs at once point said custom maps would count for it. Is there lag yes one of the reasons you are unlikly to kill them all. I would guess if you did take the time to kill them all would be easy 50M zombs on the map from the start between whats in the citys plus on the map. Every corner every space it literly packed with them on a open field with zomb capitals all around to spawn more. There in 15 min you will kill about 250k zombies and that is mabye 1% of the zombies that start on the map. Or set two waves to go of at once there is no forced cap like you say that prevents you from spawning more than a set amount. Just add another spawner and you got more. Those are the max you can set per spawner not per wave.
So, I'd say the max per wave is about 40-50k. Originally posted by CancerStrike:GolfOffensive:Per wave you can spawn in roughly max 5k per unit type.