For fixed nonroaming party, maybe we can assume there are a finite number of mobs M within radius R of the party and they repop at rate P. Then if party kill speed > P, M depletes until it reaches zero ie no mobs are up within optimum pulling range. At that point puller either needs to go outside R (long pull, may break chain) or wait for next pop (= kill delay and may also break chain).
Isn't that how it works? Suggests that in that situation switch to roaming party is optimal (which is how my best meripos have usually gone although it's been a while). So overall party strategy and behavior more important than having a puller that can fly.

Rate of repops eventually becomes limiting and forces switch to roaming strategy if your party is very strong.
Anyhow, if that's wrong then let me know. Thanks.