Paly has its niche in hybrid setups as a second melee and can be included in full melee setups, but in both setups it is more of an optional last slot, not a mandatory one, and competes over it with the other melees/hybrids. In that it is comparable to champs, which are one of the possible melees in a 4/4 or 3/5 tanker, but not mandatory, like e.g. a vw. They already got their dmg buffed, more spec points and the possibility to spec det. Paly is fine on paper, but tends to not get invited due to the meta.
Regarding your suggestions:
In.Flames wrote: give him cele, stoicism or any other gimmick
If palys get celerity, my guess is that it
a) puts him on a mandatory slot in melee groups.
b) turns him into a totally unbalanced beast in solo/smallman scenarios, where he already shines out, because he gets a xx% (depending on value) flat dmg increase due to the way celerity works.
If palys get stoicism, my guess is that it causes
a) other hybrid-players to demand it which would lead to homogenization of melees all across the board.
b) no real change in palys groupability, as any arms will still outperform him, especially because of the available RA's.
I can't really think of other gimmicks paly should get. In addition to his toolkit paly already has recieved the afore mentioned buffs, has access to the group-friendly RA's VR and AotG. My first impulse was to think about AM, but as many alb groups, especially tankers, already run two minsts, having AM three times in a group may be a bit excessive.
tl;dr
Paly only has its niche and I have no idea how to get him into alb groups via buffs.