There most be a starfleet-wide regulation that decides what is permissible and what is not and, at least for the timeframe of TNG this must have included that counselors are allowed to wear civilian clothing (at least at the CO's discretion)
And I'm just saying that Jellico shouldn't be commended for enforcing his own preferences. And even in the wider story-arc of TNG find him telling Troi to wear the uniform problematic, since the change stuck. A major change in her character happened because some man told her to change it. No bueno.
I think Troi should have decided for herself that she wants to wear the uniform (in season 2 or 3 preferably)
Of course it was all just a flimsy excuse to give Marina Sirtis' breasts more screentime (about which she wasn't happy anyway)
See I don't think there was any such regulation. We do occasionally see male extras with mullets, so I think Worf's shorter hair in the early seasons was a personal choice, which would fit with him being the overly-correct type.
We do see a couple of Klingons with short hair similar to Worfs's in DS9.