IF this team overachieves this year (wins ~80 games), and IF pitchers like Fried and Newcomb and Folty show they are ready to anchor the rotation, and IF the Swanson/Albies duo shows they can produce a combined 6+ WAR between them, I can see the Braves making a push for the playoffs in 2018.
At that point, splurging to fix the biggest hole on the roster with the best available FA position player makes sense. Plug a hole in the rotation with a vet like Lackey, get a competent RHed 4th OFer, patch up 3B somehow, welcome back a healthy SRod, and you can see an 85+ win team in 2018 if you squint.
If the young pitching falls flat on its collective face like they did in 2016, I don't think signing a premium FA makes sense whatsoever.
I just don't like giving that kind of money/years to a catcher at his age no matter the reason. It is extremely unlikly that it will be a good investment given his age and the historical track record of catchers. I think it a much wiser investment on the Braves part to spend $35M per year on a guy who can be a young cornerstone player for years who fits both offensively AND defensively (someone like Machado) than to spend $20M per year on a guy who almost certainly is a bad long term investment. The philosophical risk can be debated ( excellent young cornerstone player who cost a lot in terms of dollars and years vs aging good veteran who costs a relative amount of a lot for shorter years and lesser but still significant dollars).
Let's say you get Machado after 2018 at 10 years $350M (age years 26-36) at an average of 6 WAR per year (6 WAR accounting for minor injury, off years and diminishing performance) and you sign a catcher that produces an average of 2 WAR per year, every year over that 10 year span at an average cost of $15M per year (would be nice if the Braves could get that in house at low dollars but looks unlikely). That gives you 80 WAR over 10 years for $500M in salary.
OR, you sign Lucroy for his 32-37 after 2017 at 5 years $100M at an average WAR of 3 per year (again factoring in decline) then signing a 2 WAR per year catcher after Lucroy goes and also signing a 3B to provide the rest of the WAR value at an average annual rate of $7.5M per WAR. 15 + 10 (10 year catcher WAR with Lucroy) = 25. Lucroy cost for 5 years is $100M, other catcher 10 WAR x 7.5= $75M. Combined catching cost = $175M so
80-25= 55 WAR balance
55x$7.5M= $412.5M
$412.5M + $175M = $587.5M
All assumptions being correct signing Machado would bring back $87.5M in extra value and that doesn't even consider the possibility of deferred money or contract opt out clauses.
Obviously the long term commitment is more risky that the shorter term commitment to Lucroy but because of Lucroy's position, it's entirely possible he gets bad fast and never recovers, even without injury. With Machado you would have to worry that you don't get a guy who gets paid then quits working (the injury risk comes with any signing and is always there). But Machado's contract would be for his 26-36 YO season so, assuming no career threatening injury and you get 6 WAR out of him every year on average through his 31 YO season then an average of only 3 WAR per year after that, that's a shortfall of 15 projected WAR from the beginning of the contract meaning you lose 15 x 7.5 = $112.5M in projected value. SO the real risk in viewing the two deals would be 112.5-87.5= $25M.
And since the argument is that Lucroy
might be worth the stretch contract after 2017 because the team would be close to contending, I would argue that Machado would be worth it even more after 2018 because the team should be even closer to contending and would have a bigger impact on the offense AND defense, as long as the 2 WAR from catcher you receive comes primarily from defense in the Machado scenario.
The question boils down to me that the Braves have several holes with both 3B AND C looking to be hard to fill internally (unless you believe in Ruiz or Riley...Maitan is way, WAY too far away to even be considered in the conversation). If the Braves sign Lucroy, it's almost certain they will also have to sign a 3B as well. I think it's a better long term use of the funds to pay what it takes to get Machado (within reason).