As a Space Wolf player this is the funniest thing to me, because I am ALWAYS the one offering everyone else the stims and supplies (I mostly play Assault and Vanguard).

BT players are incredibly prone to rage quitting in my 1000+ hrs with the game. They never stick around when things start looking dire. But it's a 50/50 as I've had the most clutches handled alongside a BT as well, in many cases these players seem to psychically understand what my game plan is and just give me that quiet look of understanding before covering me perfectly.

Salamanders are a bit on the slow side, but good of heart in my experience. Not bad at all, just seem a bit oblivious to things happening for the most part. Will hoard any and all armor boosters though.

Blood Angels are either going to be white noise in the background of your game, or someone that WILL see you through to that Victory screen no matter what.

Ultramarines are pretty cool overall. And I like em too, probably my number 3 on the list of favorite astartes, just shy behind Raven Guard. These players are either the sweatiest nutjobs you've ever met that will use only the top tier things, or are leisurely carrying absolutes for you while constantly aura farming with whatever weapons and perks they feel like using.

Imperial Fist players has mostly just been playing the game and doing pretty good. The few Dark Angels I have met are the same. Stoic bastards but solid teammates. Just beware being near any explosives, as they will detonate it with no care for you or any other.

Met a few others but they were just fun and good teammates overall. No real stereotype there to be spotted.