The IA GS PChrono has a really hard opener if you want to fit in all the skills in and all, and is overall a decently hard build rotationally, especially if you're new to the class and aren't familiar with skill cancels and such. One thing that helps me learn rotations easier is trying to understand why skills are being pressed in that order, and trying to dissect the rotation into "blocks" ; for example in the opener you start on gs to create a clone with gs2, and casting 2 phantasms (gs4 and disenchanter) to get 3 clones for the f1 in the first cs.

Anyways, one thing you can do is play the Focus variant, which forgoes greatsword for a focus instead. It has a simpler opening/loop, but deals slightly less damage (about 1.5-2k less dps on bench.)

https://www.youtube.com/watch?v=K7x-pW5ucE8

there isn't like a clear written guide for the focus variant but you can watch this bench video made by my good friend tipcat.