Yeah, I think this is common in a lot of leagues. In my main league, the core group of guys have been together for a solid 5-6 years now and there trading tendencies never vary.
Commish: offers fair trades that make sense to both owners, but you can never get one by him. you have to be a straight shooter, but he is willing to trade. trade grade: B
Gambler guy: must be OCD, because he always entertains trade offers, and often makes them even if they don't make sense. there's been times where i thought i was raping him, but it ended up to backfire big time. ex- acquired lamont jordan rather cheaply after his breakout season, he goes on to be a total bust. though, he did offer me the best trade ever: peyton manning for my david carr and santana moss in a 6pt per td passing league. i snap accepted.
trade grade: A
Car salesman: in the 6 years, i've never once accepted a trade he proposed. it's always the same garbage: 2 or 3 of my mediocre players for one of your best players. sorry bro, quantity doesn't trump quality.
trade grade: D
Stubborn guy: i don't think we've ever made a trade. he simply overvalues the crap out of his players, and will not entertain offers unless he is clearly raping the bejesus out of you.
trade grade: D-
Mr. I just show up for the draft and set my lineup: Gah, proposing trades to him is like talking to a brick wall, useless.
trade grade: F
Jedi Master: this guy is up for trading at any time, but he tries talking non-sense and jedi mind tricking you into taking dumb moves for your team. it actually worked in our baseball league, since he kept offering me OK, but not very good offers, he confused me into offering him a bad trade for my team. however, he can occasionally be had
trade grade: C
Mr. Nostradamus: Not a joy to deal with. Another case of undervaluing your players. He uses reasoning like "well that guy is going to get injured" so I need x extra. He will be referring to a player who had one minor injury in his career, lol.
trade grade: D
Mr. Unknown: Has only been with us for one year, but he does have a tendency to gamble it up, so has the looks of a good trade partner.
trade grade: INC (with potential for high marks)
Mr. Unknown #2: Don't have a read on him yet, but seems very conservative in general. In other words, you're not going to get good value from him. Here's a trade he offered me after week 1: My Hightower for his Lee Evans and Darron Sproles. Thanks, but no thanks. :-b
trade grade: INC (expecting low grade, however)
Overall, our league isn't bad thanks to a couple of owners, but i don't even bother with a lot of them unless i have a player or position that they really, really want or need.