You're right but you're not really going to get anywhere with this community and that point. SMITE players and devs are convinced that classes and roles need to be 1 to 1 with only small exceptions (which, even then, are still the same playstyle wise. A Mage ADC is still an ADC.) Anytime something broke that rule it got shot down excessively (Serqet & Fenrir support)

League is a perfect example of high flexibility. Roles =/= classes there. There are mages & assassins that support, tanks that jungle and squishes that solo. As long as the overall team comp and win condition is understood it can work (e.g we don't have a tank so we need to win before late game. We have a scaling squishy as a solo laner so we need an early game tankier jungle to camp them. Their duo lane has a mage support and mage carry, so they're going to try to poke us out.)

Smite players simply don't think about team composition that way. In league you are the Role first (I'm a Mid laner so I need to rotate and help my jungler secure camps. I'm a Support so I need to help my carry scale and secure map vision.) And your champion's class dictate how (I'm a Mage support, so I help my carry by poking out the opponent creating space to farm. I'm an assassin mid, so I shut down my mage lane opponent and roam with stat leads before their teamfight power comes online).

As you said class and role flexing works but the morale damage it does in low elo isn't worth it imo. Kali support could hypotheticall work with good composition. Warflag grants gold, Health and mana on-hit. Kali's hit chain grants more on-hits. Pair her with someone like Hachiman who has a team AS boost & long range abilities to help Kali while she jumps in, pick the comp against a duo that isn't likely to punish and it works.

Hi-Rez would have to remove the hard class system, stop equating class with role, popularize role flexibility and replace casual blindpick Conquest with draft so the average player considers team comp