Unit variety is another subject that we will need to address soon.
This game can`t have a huge unit variety because it will 1. fck up the balance of the game 2. you will have multiple units performing the same thing....
Also what you said with the popcap. You misunderstood me. Let me give you an example you get 2 cons at the start, reach 2 teritories at almost exact time with 1 cons and 1 engie. You cap them and get more population at the same time you get 260-280 MP so you make another cons squad. This won`t change the meta.
If by spamm you mean less units from start then a simple reduction to the MP rate will be sufficient imo. But this will make the game much much more slower and the early game most porbably will last longer.
But if by spamm you imply less exact same units then your idea will not work imo.