Considering all troops to be no xp, no research, no general, no terrain disadvantage, no doctrine etc. (Basically completely even)

What amount of infantry would be evenly matched to about 1k tanks? (Just want an ratio for the early game)

Also, let's say for whatever reason, I cannot or will not use tanks to get rid of a massive infantry army (about 500k - 2m). What methods can I use to destroy them, in both offense and defense, in any stage of the game, respectively?

I like to play as pakistan because, unlike Iran, it gives me a challenge when India is present (I usually become a superpower if not) and I'm relatively skilled at exterminating tank invasions from China or Iran, but India almost always spams infantry and tho he usually takes about 3x losses than me, I usually lose after his 3rd or 4th wave. I can't afford tanks in the early game, and their training time lasts longer than this quick war anyway.

I know how to terminate forces attacking my key cities, but I can't afford to build a Fort everywhere, so I would like to know ur anti-infantry strategy (other than tanks). Ty