There isn't a coach in the land would be happy to see a try scored inside a winger...if the centre goes, the winger goes, it's all about communication. the modern day game with precision like set plays, bigger bodies, and better athleticism, it is impossible to simply number up your opposition. If you leave defenders isolated one on one you will get burned. So the logic is to to push the play as wide of the ruck as possible to keep hurdling the opposition further sideways. If an opportunity happens to open up on a flank, you make them work for it, make them throw that extra pass, make them hit that winger with a long cutout pass because there is a better chance of it going wrong...it's all about he law of averages. If you simply stay out you meekly surrender a try closer to the posts.