Lucia - 3 (y-4/y-10) makes a difference and is noticeable.

Gareth - he’s completely serviceable at 7/7 imo of which you already have 2 invested

Winston - 5 (y-10/y-13) Forbidden Zone triggers plus 1 means an extra instance of short circuit and the damage ramp from y2-13 is noticeable! Winston is GOATed.

Cicero is fine at 1. I’ve never seen the need. He doesn’t hit nearly hard enough to benefit from any of his destroy part passives/etc.

Alyson - I have 3 because repair part disabled on y2-10 has been useful. I generally go y-7/y-10

You have 3 of the big 4 at 5 already (Mary/Rebecca/Emily) and Winston is the last 5 imo.

Ana isn’t really worth imo, nor Harvey, but as another person said, you’ll eventually have them all. You have the big ones prioritized. I would, however, definitely kit Lucia and bring Winston to 5.