I think it's safe to say at this point that RH's rebuilding trades have put this team in a position to make a jump in 2020, and your evaluations of each of those 3 trades, while somewhat optimistic, aren't unfairly so.
However, those are not the entirety of Rick Hahn's trades. There's one in 2016 that we still will not even mention in this discussion, but even ignoring that one, Rick Hahn remains the 2nd best GM the Athletics have. These down years were substantially caused by Rick Hahn being willing to sacrifice years down the road for his winning teams in 2015 and 2016, and the trades where he gave up guys who are now solid big leaguers were a big part of that. Yes, several of those guys took a lot of work, but Oakland did that work and now they have several solid big leaguers out of it. Rick Hahn is the difference between Oakland being a .500 team and Oakland being 5 games below .500 right now, and they have been less lucky than we have.
And yeah, I'm going to drag the Colome trade into this too, because it still was not a smart move. We gave up a player under team control for 5 years for one under control for 2 years. At least last year, we should have been doing the exact opposite. If we did that because our staff is too lazy to work with a catcher on their development, that is not an excuse. If we traded Colome for a young catcher who currently was putting up solid numbers and had improved on everything in his game year over year, we would be saying "There's a good chance our catcher's spot is solved, maybe it's not with an all star but this frees up money to go sign Cole and we can move Collins to 1b right now". Instead we're still talking about Grandal and wondering if Collins can play there. That trade fits in with the trend of his previous ones - making moves that are too aggressive for his roster to support, giving up on guys because either he can't see how they could develop or because his organization is too lazy to deal with them.
We're probably going to have to do some moves like that next year to find a pitcher or two, and that move doesn't look particularly good in the light of him making the exact same kind of mistake with guys in 2015 and 2016.
So I'll go so far as to say that RH's rebuilding trades are showing positive promise this year, but his "Win now" trades for established big leaguers have been setbacks for the franchise almost every time. Heck, that phrase describes his first couple years too.