Shan would transform the mentality of the side. He went from an untalented underperforming cricketer, to learning to dominate in domestic cricket, with the highest list A average. In t20s, there were remarks he was too slow. In order to push for his place, he tried to transform his whole game, performing in english domestic T20s, increasing his power hitting, and being more inventive with his shots. You could see he tried to apply this new found game to international T20s, but it didn't work, and he just went back to being conservative again. Both Multan and english sides responded well to his captaincy.
The guy has shown immense application on improving his game, in both performance as well as trying to modernise his game, all while keeping great fitness standards. I haven't seen many Pakistani cricketers that have done that. It's just a real shame he just naturally isn't talented enough or good enough for his place in the side. Usually the guys in the team are either talented and don't work hard enough (umar akmal, Sharjeel etc.) or there are guys who more play within their limitations well (Rizwan comes to mind). Shan had to pretty much go from nothing to get to the level he is now, which is hugely impressive.
I'm sure a performing Shan as captain would inspire others to keep fitness and fielding standards high, actually look to develop and improve their game further rather than resting on their laurels and thinking your good enough. But obviously if he's not performing, no one is going to respect him. So it sadly won't work him being captain.
One thing you can see in say previous captains is they didn't have that mentality. Sarfraz let himself get unfit, deteriorated in keeping and batting. Misbah kept his fitness and batting up, but resigned himself as being that slow anchor batter in the middle, down the order. Misbah had power in his game and probably could have better rotated strike, he could have done more. Babar hasn't developed his power game and some other parts of his game. If you look at Kohli he was similar to Babar early on, he didn't have a power game. But he focused on improving that. I genuinely think Shan has thrown the kitchen sink at trying to improve, if he had the talent of our other cricketers, I think he really would have been something.