Assuming health, it's not that hard to get to 80 wins on a pure WAR-driven basis. If you project something like this from the guys we have:
Freeman - 5
Inciarte - 3.5
Swanson - 3
Albies/Peterson - 2
Mallex - 2
Kemp - 1
Teheran - 4
Folly - 2
Wisler - 1
With those totals, you're sitting at 23.5 WAR, putting you around 71-72 wins. You need around 8-9 WAR at that point between 2 SP spots, 3B, C, your bullpen and your bench.
If you just add solid pieces at 3B, C, and SP, you're basically there.
I think you are probably on the right path, though I think Mallex is more of a 3 WAR guy. I would prefer to see something like this:
Freeman - 5
Baez - 4 (Inciarte trade)
Swanson - 3
Albies/Peterson - 2
Mallex - 2
Markakis - 2
Mac/Flowers - 2
Kemp - 1
Teheran - 4
Folly - 2
Wisler - 1
That's 27 WAR, or 75 wins. A decent 3/4 added to the rotation and the BP/bench kicking in a few WAR could quite possibly get this team to 80+ wins. At that point they are some luck and a nice trade deadline addition away from being a fringe WC contender.