I like a lot of what you've said here, but I would just offer a couple 'disagreements'. First, that's getting extremely optimistic to have a 2019 ETA (even if only 'potential') for the guys who have yet to play in the system at all. It's hard for me to see guys like Pache, Cruz, Wilson, or even Yepez being ready at that point. And while Maitan could possibly fly through the system and be ready, that's pretty crazily optimistic on him as well. And I don't see any shot at all for Gutierrez by then.
And as for that potential OF, it would be seriously weak defensively. Riley has a cannon, but I can't see him moving extremely well in LF. And I don't see any way Maitan would fit in CF, even at that age. He's going to be huge.
The main point is it's entirely possible that our lineup AND rotation could be homegrown by 2018/2019/2020 with quite a few inexpensive high-ceiling players. Combine the game's increasing revenues with the Braves' increasing revenues from the stadium complex, and it's definitely not hard to see us as potential major players when it comes to signing players from the monumental 2018 free-agent class. Keep the Pitchers, throw 8 years and $240 million at Machado, and call it a decade...
2B- Albies, SS- Swanson, 3B- Machado, 1B- Freeman, DH- Riley, RF- Maitan, LF- Lazarito, C- Gutierrez/Herbert, CF- Mallex