He's not going to be able to compete with corki/graves on bottom lane, and he can't compete with the utility of ashe, or the tank destroyer vayne, he's a mediocre ad carry at best. 500 auto range isn't very good. He can't ap mid as most of his skills scale off ad. That leaves top and jungle which a lot of champions can go in either. You literally missed the point. If you were to pick any of those it would be pretty obvious what lane they're going. Easy to pick something that works well against them. Can't really do the same with Jayce it's only viable to counterpick an after laning counter. Eh, same can be said for Jarvan. He could literally go all four lane and still be considered viable. Solo top Jarvan and jungle Jarvan is standard, Jarvan/Leona kill lane is powerful too, he can burst down most AP mid with his early game damage AND he can even play support if forced to.