SMN is the dps job spec for Arcanist. It's going to be the same as the base class, thats just how it works.
What you're asking for is not only a change in the SMN job itself, but an entirely new class that would function completely differently. FFXIV is not built to allow a pet focused class to function. It just won't work outside of you becoming the pet outright to remove your character from the game, at which point you stop being a pet class and are now a shape shifter.

And a bigger egi won't work because it will get in the way of other people having to target or seeing mechanics and many things. It's already bad enough when a Lalafell gets targetted by Divebombs or Devour and there's highlanders/roes in the party. And for the same reasons, a miniaturized version of the primals would just be shitting on their power. I'm pretty sure Titan-egi takes more resources to animate than regular titan as well, because while he's smaller he has more stuff going on.