its not about being a good team mate, its about leaving lane at the right moment. When you alt to an ally can make or break a game. You literally need to be watching other lanes as you play your lane.
Shen plays well in to tank cause of his % max health damage. Losses against Rivan, Fioria, Yas types as the game goes on. Once shen falls behind he will stay behind. Does not do to well laning against mages, but they are rarely in the top lane.
Shen is about playing smart; not being flashy.
You can take any champ to a high level if you master them and game.
The real question will be do you like Shen enough to main? I just main tanks/divers/juggernauts and can play almost all the champs in these classes.