Astros have wanted Stroman in the past, and Yankees definitely would want him. So the rumour isn’t exactly out of left field, but a bidding war between the two is difficult to see. There are other teams that wouldn’t mind having a good starter, it only takes two parties.
I’ll bite just for fun, in this case specifically, both farm systems have a crap ton of young assets or prospects to pluck from. You’d have to raise the price tag to NY just because there’s a very real risk that Stroman would re-sign and pitch against us for long term. If you can get like a Jonathan Loaisiga + Deivi Garcia from the Yankees, that would be a haul. Or substitute one for Luis Gil + Albert Abreu or something. Frazier would be fine if he isn’t the only asset coming back, but with Gurriel looking great and Grichuk locked up, one of them has to play CF which makes guys like Teoscar, Alford, and McKinney almost obsolete. I’m not the highest guy on Frazier though, but there’s potential there.
Astros are a bit tricky. The guys you want are untouchable (Whitley, Tucker, Alvarez), their good crop of pitchers coming up seem to be struggling a bit, or moved into the Astros bullpen. Names like Corbin Martin, J.B. Bukauskas, Josh James, Cionel Perez, Framber Valdez, Bryan Abreu, etc. I’m not completely sold on Corbin Martin despite the higher ranking and might lean on Bukauskas just cuz his stuff is so nasty even though his minor league sample isn’t huge. They’d have to add more for Stroman, but I don’t think they’d want him enough to do that.