SE, don't overthink Summoner 7.0. Just give people what they want. Just do it.

[Ggwppino]

the smn had a 2 minute rotation, sure. But technically they were just variations.
If we introduce 3 new filler summons, they will have different characteristics from the 3 we have now. And if, unless they are a copy paste of the current 3 summons, it will be a profoundly different rotation and it will not be just a variation of ruin 4 and tridisaster.
moreover, if we consider a hypothetical alexander after the umbral phase (1 minute) and an astral phase (1 minute) alexander would heavily change the timing of these two phases (too long to be so different).

furthermore I am deeply convinced that smn doesn't need new skins, but a revamp of its gameplay which is currently based exclusively on pressing, almost without thinking, 2 buttons. And adding more summons in sequence won't make his gameplay better, only more glittering.