Misha likes to fancy himself a top/dom/alpha because he grew up without a father so he's (as hellers like to say about Dean) overcompensating his masculinity, especially after being cucked by his (ex)wife with another woman. Remember kids, when a man is involved in a threesome, it's always with 2 women, never with another dude. That scene in Mist of Avalon would never have happened, those who read the book or seen the tv mini series know what I'm talking about.
Sure I think Misha resents Jensen, though not for the same reasons you may think.
First, in general actors are not friends and the massive pay gap between Misha and the supporting actors and J2 is only natural, but it doesn't have to be nurtured. Gratitude goes a long way to temper entitlements, jealousy, and resentments. The industry is tough and it never ceases to amaze me how many chronically unemployed supporting actors of long-running tv shows seem resentful and entitled even though they still make decent money from conventions during their long bouts of unemployment. I've witnessed this with casts from Star Trek OG to Beverly Hills 90210.
Second, Jensen didn't want Misha near Jared because males in general don't like male interlopers into their circle, and also he didn't want them to become friends because it could lead to an off chance of more Sam & Castiel scenes, which will not only cut down on screentime for Dean, but also his screentime with Sam. Every ambitious actor wants screentime with the lead actor to further their career, but Jensen played his part make sure there aren't many Sam & Castiel scenes.
Third, while Misha can't bash Jensen like he does with Jared because of the fake ship, it's worse for Jensen because he can't come out and deny the ship or else get the repeat of 2013 debacle.