i would personally do that trade. branyan has played well for over 2 months now so i just dont see him falling apart. plus getting arguably the top pitcher in MLB is great. in turn you could flip santana for haren and another pitcher maybe.
for the downgrade you would be making at 1B I don't think this is worth it. Johan is great but for a 16 team league your rotation is pretty solid and Teix should keep putting up great numbers while Branyan is no lock to stay hot all season. If you really want to make a deal I would try for an upgrade at 2B
Teixiera is a stud and is usually a 2nd half player. So he will def keep up this pace. I think Branyon will come back down to earth. He has never in his career hit for this kind of average. He strikes out a lot. I think its all down hill for Branyon at this point.
Johan is a stud, however for a 16 team league having Gallardo, King Felix, Scherzer, and Ervin Santana is pretty solid. Nolasco is pitching well now, Jimenez is a decent back of the rotation starter.
I think you have enough pitching and you would lose more than you would gain if you did this trade.
fair offer, but i agree with most- stick with teix. santana probably wont be a difference maker for your already solid staff, and branyan cant be fully relied on to have a second half to match his stellar first.