Looking at a couple of Arsenal stats..
Sokratis' heading at 13 feels low, he's been very useful for us both attacking and defending set pieces in the last few seasons. 14 or 15 maybe?
Without seeing the exact figure it's hard to say, but I feel Rob Holding's max potential should be around the 4* mark. He of course may not reach it, but only half a star of growth left in him feels harsh.
Mustafi's positioning is very generous. He's always playing reactively and throwing in desperate tackles. This is reflected in his concentration perfectly, but the positioning should be brought down to a similar level.
Is there a trait for Maitland-Niles to be so laid back that he could be on a beach in the Seychelles?
Guendouzi's 15 Acceleration and 14 Pace could be nudged down slightly. He's not all that quick and can resort to fouling if he comes up against pace. See Zaha vs Palace as an example.
Xhaka's agility is for sure, too high. A lot of Arsenal fans' (pre-Palace) gripes with him is that he slows down the play far too much and turns slower than prime Mertesacker. Bring it down to a 9 or 10?
In my opinion Nicolas Pepe should have a bit of a higher rating in free kick taking. Admittedly he hasn't scored loads of them, but the two he scored in the Europa League were of a better quality than that of an 8 rating. I'd push him up to into parity with the likes of Xhaka and Lacazette who have 13 and 11 respectively.
Gabriel Martinelli could do with a bit of a boost in a few areas. Crossing, Finishing, Passing, Anticipation, Balance to name a few. Also a potential boost? He's a 2.5/3.5*. Lift that to a 3/4*? I can see how he has been hard to rate though, after coming from nowhere. He also just wears Martinelli on his shirt, not the full Gabriel Martinelli that comes up in the tactics screen.
Maybe a bit of a boost in leadership for Bellerin and Aubameyang. They're currently set at 4 and 6, and while I agree they've not shown amazing levels they could be in the range of say 9 - 11, based on other players in the squad.
Otherwise I'm very happy with the Arsenal ratings. The researcher has our lack of determination down to a tee and the personalities are spot on.