I decided to give it another test and it doesn't seem like accuracy affects infect chance at all. Unless you meant the increment that happens when you level up a stat, in which case it does, but I meant giving it its own infect chance boost separate from the one you get when levelling up in general.
Giving it another little playthrough I'd say infecting might be a little better than I previously thought, but only once you have a character fully or near fully levelled. Paired with high movement it opens up a handful of cool fun strats like walking up to an enemy, attempting infection, then using the remaining move to hide behind cover if it doesn't work, or putting yourself in a better position to shoot another enemy if it does. This could be really fun to experiment with if there were more challenges, but alas.
Also finally figured out that the stats of the new recruits are directly copied from the enemy they came from, which also explains why all new recruits have the exact same stats lol. Cool attention to detail having the guy in the ending 2 frame change color to match the generated unit too! I think that's about the most fun I can get out of this unless it turns out I missed something huge... or I could try to see if you can beat the final mission with just one guy. Maybe? Maybe not? Perhaps. Would probably need one of the orange dudes to do so.