HD, I have 25 plants but I also sell lots fresh to the local hispanic population (I sell more tomatillos than tomatoes...)I would think 5 plants that have these larger sized tomatillos would give you PLENTY! You got seeds from those coming.
All I know about staking tomatillos is they are really fragile compared to tomato stems. They just kind of shear off. I have tightened twine around them and had it cut through the stems like a scalpel. Big yarn works a lot better. And the gosh darnoodley things are the "Sprawlers" of the garden kingdom. If you just leave them, they are as wide as tall and they will cover up anything nearby. I also put black plastic under them to make it easier to get the fruit that falls when ripe and it helps with the re-seeding problem (these re-seed worse than any tomato I have ever grown. And then I feel like a "murderer" hacking all those little tomatillo plants to death
) My family prefers the Salsa Verde to Red Salsa. They eat it on everything...eggs, meatloaf, pork chops...