In the bottom line the spam is "the maximization of number of cheap unit you can place in game using a certain amount of money/resources".
Taking into account this definition, the quotas you suggest are useless. If i want to spam i just need a combination of cheap units that maximizes the ratio between quotas/resources .
Paradoxically, settting this limits damage me as defenders because i have less freedom of choice.
We must accept the truth: you can play an rts in 2 ways. The first one is spamming cheap unit. The second one is using a limited number of ("well microed") high tech and expensive unit.
Except than WEE is more than wargame than an rts like starcraft. As a wargame we sould'nt be allowed to spam one type of unit and the army on the battlefield souldnt have the same proportion than your deck.
Now i have no problem with the spamming of cheap units like 30 tanks, 10 heli, 20 infantry but not 64 tanks or 40 heli and noting more