I think the conclusion you need to draw there is that we lacked physicality in other areas of the team - yes, Morgan is slight, but you can afford to carry a slight player who brings what he does to the team. What was needed was more physicality around him, to soften defences up, to be more imposing in the middle of the park, etc.
Last season, if players went through Morgan, they knew there'd be no comeuppance. Jim Goodwin the player would never have stood for it.
I keep banging on about Curtis Main at Motherwell, but in my mind he's precisely the sort of striker we need to be looking at bringing in.