Would you consider looking at Grounded as a Diver-ish effect for the Diver Update?
#Changing a semi-reliable stun to a semi-reliable grounded debuff is still a nerf!
Just needed to get that out of the way to qualm some trepidations about giving Divers anything. Enough people hate them as is. The goal here isn't to buff Divers or nerf them, it's to establish their class identity and make them healthier, improve the game, improve their gameplay and so on. I believe this direction could help do that because it a) would separate the resources Fighters and Tanks can offer and b) it fits a lot of Divers' identities really well. Just imagine grounded was named hamstringed, hobbled or challenged instead. These are fighters who want a good battle, or a duel, or a brawl -- whatever you want to name it. They don't go around knocking weaker enemies out cold and then pummeling them to death.
Plus, like I said, giving some of them "stuff that fulfills the purposes of a grounding effect" instead of a direct stun is still a nerf. I say some because not all Divers would have to have a grounding effect forced into their kits. It could just as well just be "stuff that fulfills the purposes of a grounding effect", things like Warwick's and Lee Sin's Qs, or Kled's E, things that counteract the dash/flash type of mobility and that type alone. Of course, that nerf would also be compensated accordingly.
Divers I could imagine actually grounding enemies, though, after an update are Irelia (hamstring), Pantheon (shock & awe), Xin Zhao (challenge), and Lee Sin (hobble; if his Tempest E had a really tiny range and briefly Grounded enemies hit they could remove the auto-root on his ult --> Lee needs to hit his E in order to get a reliable ult. Landing his Q might give him automatic access to that E but he'd have to hit the Q first, not last).