I believe in their starting ship wingmates have normal unadjusted fire rate (unlike most other non-player ships). However, after buying Jenna a new ship (that I customized) with Hanzo blaster, she was firing only about 4 shots per second compared to the shown fire rate of 10 shots per second of Hanzo blaster. The same happened to Volkov - I bought him another ship with dual x-ray and he was firing noticeably slower than before.
On another note, I noticed that friendly fire from the player to wingmates/autons is off but friendly fire from wingmates/autons to the player and to each other is on. Is this the intended behavior? I can understand this because enemies have friendly fire on and without friendly fire a fleet of autons and wingmates would have much more firepower.
Other small things: 1. Directly buying a wingmate a new ship (without first buying it yourself) turns their color from white to teal. 2. If you buy a new ship for yourself sometimes your old ship runs away so you can't buy it back anymore. It's annoying if you're trying to customize a ship for your wingmate.
I didn't even know you could buy wingmen a new ship!
That's because character's ship AI setting was not carried over to the new ship. They will used stock NPC ship AI which generally slower.
@digarw: That's my first guess too. Definitely a bug that needs to be fixed.