Synergy here doesn't work that well. Mara and the Ossus don't need Garm since they have Twin. Ithorian only boosts the Ossus and Jarael. And no door control is a pretty big issue.

If you're playing competitively, you have to have door control to make sure you don't get locked in a room. You typically need at least 2 or 3 pieces, but if you only have one the ERC is a good choice with stealth and a lot more hit points.

Garm is pretty expensive to begin with - it's a good CE (what GMA should have been in the first place), but you're paying 15 cost for it (Garm's cost minus 30 reinforcements). It only affect Jarael and Ganner, and Ganner will often be levitating instead of attacking so he won't get full use out of it. Seems like a lot to pay mainly to let Jarael move 4 and attack 3 times.

Bringing in the Ithorian from Rebels is a great idea, but the cost is more than just the 11 printed cost. It also means you have to pay for Garm's relatively inefficient CE, and with either the Bothan or ERC you end up wasting 2 or 3 more cost in unused points. Just saying that if you go through the trouble of bringing the IC in, try to get the most out of him. I'm not sure Jarael + Ossus is enough to justify it with the extra overhead.