madmagicianNo, no. 50% trusted. 33% of an army must be sponsors if sponsors are taken. The two overlap.
Blood Axe Kommandos are Orks. They have been known to work for the Imperium as auxilia.
The Cargo Lighter is a mercenary because Cargo Pilots aren't useful for intimidating shifty aliens into line.
The Demiurg are Squats, basically. Squats with Mole Mortars.
Eldar Pirates are kind of self explanatory.
The Hrud are sneaky little vermin who use warp-plasma and who have warrens. They appear to be basically Space Skaven, but have varying depictions. I've leaned toward Space Skaven.
The Kroot are mercenaries as well, who mostly work for the Tau, but also work for others. They eat their enemies.
The Loxatl are weird lizard-things.
The Nekulli apparently appeared in the Inquisition War trilogy working with a Rogue Trader.
Ogryns are, well, Ogryns.
Scythians were almost wiped out by the Crimson Fists. They're warrior monks who favor poison and duplicity, and managed to kill the Crimson Fists first Chapter Master.
Tarellian Dog-Soldiers showed up in the 3e 40K rulebook, and are evidently famous mercenaries.
A number of the above races apparently don't like humans much, but I'm assuming that money helps overcome such feelings.
I'd recommend looking at
this link, which was my primary source. If only because nothing else was generally available.
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ApocolocyntosisGo for it, then.

That's a large part of the sponsorship - to facilitate doing so. All you need after that is a few aliens, and there's a lot of 6mm ranges to choose from (and a lot of existing armies to draw on).
The 30% rule is to prevent people from just taking a small number of units and knocking off for lunch. It makes more sense for there to be a lower limit than an upper limit, IMO - sponsorship feels like the sort of thing that would involve at least a moderate commitment, rather than something half-hearted. I'd see a Chapter as more likely to commit a company than a few squads.
I admit, that's a bit of weird spot with the trusted rules. I think it's survivable, though. The Eldar were originally a sponsor (as were the Orks, actually), but I cut them back because they didn't have quite enough units to make it practical (IMO). They should have more than one, though, I think.