When the rest of the teams are playing guys who average with the bat 35/40 at 7 with bowling averages of 40/50, not sure we can justify going with a bowling allrounder. Times have changed, teams aren't playing bowling allrounders down at 7 anymore, they'll take the batsman, even if he's an average/poor part timer. Just look at the NZ for example. New Zealand usually play Grandhomme at 7 who isn't a great bowler by any means. India play now Pandya (and before Jadhav). Australia Maxwell, SA Behardien. Even England play Moeen. None of these guys are particularly good bowlers, a lot of them average 50/40 with the ball. That's just part timer standard and average at best.
Making up the overs with part timers and stacking your batting is becoming the norm (it's always been the norm really). We have quite a lot of part timers already, Malik and even Haris really are better than a lot of those part timers. Talat and Fakhar can bowl too. Multiple part timers are arguably better than one sole allrounder bowler too as more options, more difficult to predict.
If the batting strong teams are packing their batting, and we're trying to boost our bowling despite being a batting weak team, there's a problem. A long batting line up gives the confidence to play more aggressively, and more bats to play with thus less stalling in the run rate.
What I can see in most teams is that 1-7 are proper batsmen regardless of their bowling abilities. And the no.8 batsman can bat too in addition to bowling. We moan about our batting, but we've ever rarely even been willing to sacrifice bowling in the slightest to boost it. We just accept our fate as a mediocre batting team.