I did it the other way--I match the drain rate to the full output of the pump using a slice gate. I have a Herbie style overflow with 2 main drains, 2 emergency drains, my pumps just run full output all the time. I sleep better at night that way because I can't see anyway the tank will overflow, and because the tank is dead silent.
If you wanted to do that in your tank, with one drain per overflow, then one drain would need to be able to the full output of your pump, draining at full siphon. If not, you'd need to drill a hole for 1 or 2 more drains in one of your overflows. Got room for that?
Either way, if you're gonna rely on drains running at full siphon, I think you better have an emergency drain.
If you wanted to do that in your tank, with one drain per overflow, then one drain would need to be able to the full output of your pump, draining at full siphon. If not, you'd need to drill a hole for 1 or 2 more drains in one of your overflows. Got room for that?
Either way, if you're gonna rely on drains running at full siphon, I think you better have an emergency drain.