So. It's from Meta-Wing. If you don't know about Meta-Wing here is a blog explaining Meta-Wing. All the usual Meta-Wing caveats about sample size/validity etc apply as much as ever.
Data is since Wave 11 release to today. Store Championships only. Sorted by list archetype. Top 2/3rds of squads only (the archetypes break up into lots of '2 people played this, 3 people played that' whereas the top 66% are pretty coherent archetypes).

We've seen worse imbalances than this in the past.

The race to the top of the PS tree appears to be back in full flow. You can tell this by just how much is suddenly happening at PS10, which is people deliberately picking EPTs to boost their PS. PS3 is mainly Contracted Scouts and Jess, PS5 is Biggs & Lowhhrick.

If you really clumsily turn the three factions into amorphous blobs of all their archetypes you get this. Notable that Scum is appearing less than Rebels, but winning more often when it does appear.

This puts a bit more context behind those amorphous blobs. All three factions have a bunch of squads in 'Tier 1.5' that are roughly as good as each other, and decline in effectiveness at roughly the same rate, so to that extent the factions seem pretty well balanced. What's swinging Scum & Rebels ahead of Imperials is that they've got the Tier 1 squads, and the Tier 1 squads are WAY ahead of the best of the rest.
Tier 1 = Triple Jumps, Dengar/Tel, Dengar/Nym, Fair Ship Rebel, Dash/Miranda

This is the one I like least. 68% of squads are significantly loaded up with turrets. 68%! What's also noticeable is that we've moved on from Dash/Corran or Han/Jake to the point where a main turret ship is often now being supported by a second turret, and not just a second turret but ALSO bringing torpedoes and bombs. Turrets and bombs in particular is like playing rock/paper/scissors with a pair of scissors strapped to a rock, because bombs nail most of the stuff that brings autothrusters for the turrets.
Personal opinion - I'd like to see primary weapons squads a much bigger %. I mean the only reason primary weapons are even >15% is Fair Ship Rebels...
Edited by SOTL