I play from a Moto G4 plus and even when there's very few units the frame rate feels low(I can't measure this but I can tell by means of comparison) once the enemy or myself decide to drop more units the frame rate drops so much that I can't timely respond to my foe's actions. This frame drop is specially noticeable at the moment of summoning, at that moment I can't possibly drop anything myself because the drag mechanism will just not respond.

I play on my gf's account sometimes on her IPhone 8 and of course the difference is like day and night, but it shouldn't be like this when it comes to gameplay. Take clash royale as an example, there I can't notice different frame rates between the IPhone 8 and my Moto G4 plus. I can run it even on an older phone without getting frame drops during a match. That's because they have of course less graphical demands but also because they tone down the detail of graphics and sometimes remove an effect altogether.

I wouldn't mind to trade pretty graphics with loads of effects for a stable frame rate so my game is not so disadvantaged against other phones. Please review the "configs" for lower specs phones.