I really feel like you're overestimating the forces likely to be sent our way, remember, the whole city is about to catch fire multiple times in a row and we're going to have some very obvious limitations, the thing that tends to make the PRT give you the kill orders is self replication and mass production, things we cannot do.
That's why the best thing would be the lizard
With the city turning upside down because of Bakuda, the best thing would be to have something that according to the QM would be able to resist bullets already at base or with little research, which we can then improve if we are lucky and get Lung's DNA
What can we do if we have a person as our creation?
It was said that it could deal with slightly trained people already at base, but that is not very useful when we are dealing with firearms, bombs or parahumans who are either brutes or have experience dealing with them
Also, if someone discovers that it is a creation (and it is almost certain that someone will do it, like Lisa or Coil) we must expect to be blackmailed or directly Piggot will bring down all the heroes of the county if he gets his way
The Assistants still have the same base as the Main Minion, though, so if we go Lizard, we'll still have a harder time improving the Assistants intelligence than if we go with Person, they'll be more fodder troops or manual labour than actual researchers, especially given we'd be mostly researching towards the Lizards improved scales and claws, which would mean improved intelligence would require us splitting our time, instead of it being one of our major research avenues like it would be with Person.
In itself, the QM already made it clear that, even if we choose a persona and improve it, the heavy lifting would still be mainly ours since we are the tinker and the creation is not
And anyway we are going to have to improve the intelligence of our lizard if we don't want it to get out of control and start killing everything that comes in front of it, which won't cost us that much considering that the lizard makes it easier for us to improve defense, which is what we need most right now
I mean, even if by some miracle we manage to go through the whole Bakuda disaster without dying or having it discovered that our created persona is in fact a creation and therefore suffer the risk of everyone falling on us or Coil coming to blackmail us into serving him, we also have to deal with Leviathan and later with the S9
As if we will have a bad reputation for being biotinkers, I say that we shouldn't make things more difficult for ourselves by choosing something that will make it almost impossible for us to survive in a place with so much dangers like brockton