Maybe being a grappler height is less of a big deal? It seems like there's a lot of grappling greats who don't depend on height:
Marcelo Garcia: 5'8"
Cobrinha: 5'4"
Yoel: 5'10"
DC: 5'11"
Palhares: 5'8"
Rickson: 5'10"
Cyborg Abreu: 5'11"
Galvao: 5'10"
Arona: 5'10"
Jeff Monson: 5'9"
But there's still guys like Roger Gracie, Gordon Ryan, Werdum, Craig Jones, Keenan Cornelius who are 6'2" or above and dominate as well. But it seems like in lower weight grappling it's not that curcial, some of these guys even won ADCC absolute div.
For striking and MMA, I would assume height and reach is more important, it's harder to generate force punching upwards and to get into striking distance for a short guy vs a tall guy, unless your game is very grappling heavy, or you're Mark Hunt.
Conor was long and tall for FW, Holloway is tall (but short reach), Barboza the same for LW, Woderboy and MVP the same for WW, Adesanya same for MW, Jones and Reyes obviously for LHW and Ngannou, Stipe are quite tall, as well as most HW boxing and K1 champions, except Tyson.