No better pace bowling all rounder currently but, Wasim Jr is being considered as one for the future as pace bowling all rounder and currently has more pace and can bowl at different time during the innings (Still a work in progress though).
Thing is Pak national white ball setup already has Shadab, Nawaz, Imad as spin bowling all rounders and with Hassan's ability to hit a few the batting depth is decent. So when it comes to a pace bowling all rounder the priority for Pak's selectors and management is a pacer first who can ball at good pace (Around and above 140kph) and can ball at different times of the innings. Wasim Jr has that extra zip and has some ability with the bat as well, both are work in progress but management things he can fit the bill for that pace bowling all option in the coming days.
Faheem after few injuries lost little bit of zip and is now mid 130s bowler and with not much ability to reverse or ball those perfect yorkers, his death over skills are highly dependent upon his pace variations which doesnt make him that 3rd seamer when Pak has number of pacers to fill that role and if they need someone who can bat a bit too then Wasim Jr and Hassan are already there. If we talk about the no 7 and 8 position the players he is competing with are spin bowling all rounders who have been doing pretty well with both bat and ball.
His ODI numbers are pretty poor considering his potential and they have not improved as much as was expected. In T20Is his bowling numbers have been decent but, then again the point comes down to is he good enough to be a third seamer or is there any specialist spinner knocking at the door (And is better than either Nawaz or Shadab) which will make Pak go with Faheem alongside one spin bowling all rounder, a specialist spinner and two front line pacers?
So these are few things which have been into play.