Reasoning on Presumed Plan : Rendon is a third baseman by trade playing second because that is what is needed. He wants to be at third, the Nats want him to be there so the sooner he slots back in the better. When Rendon is healthy he has proven to be one of the better hitting 3B in the league putting up a .287 / .351 / .473 line in 2014 and showing that kind of offensive skill in spurts during a lost 2015 campaign. He was also a superior defender at third. Assuming his injuries haven't taken that from him (and there's no good reason to think so - he was solid at 2B) Everything works out pretty nicely.
Escobar shifts back into SS, where he's played most of his career but couldn't last year with Desmond still around. This was the plan all along, we assume. A cost-effective SS replacement for the bridge year between Desmond and Turner.
If 2nd is Danny's, and we assume as much, then the Nats will have to find a bench player to be the MI/3B back-up. There isn't an internal solution unless you want to bring up Turner to sit at first and transition to a starting role. Only Espinosa, Rendon and Escobar played 3rd base last year. Uggla shouldn't be in the majors. Difo needs more time in the minors.
Problems with Presumed Plan : Relying on Rendon, who has now been injured in 2009, 2010, 2012 and
Yunel Escobar is known to be temperamental and they kept him at third because he was hitting well. He may throw a fit about being moved. Or not. We'll see. The real problem though is the Nats were hoping for a return to form from Yunel defensively after a terrible 2014. Instead they saw that 2014 wasn't a fluke and he can't hack it in the field. Moving him back to a more demanding defensive position would be questionable to say the least.
My take : You have to go with Rendon somewhere. He's young, cheap, and when healthy, very very good. He's the type of player you accomodate, not Escobar. True, I think it makes more sense to stick him at 2B. Yuney can remain as hidden as possible at 3B. Meanwhile, Rendon would be possibly the best at 2B, and the good players only run about 5-10 deep. At 3B he's more Top 5 and the good players run around 15 deep. But that only matters if you assume the Nats will try to get one of those good players. Just getting a healthy Rendon in the lineup is the most important thing. I'm not revolting at Rendon playing 3B.
Escobar playing short is unfortunate but the necessary move to accomodate Rendon. It's not optimal but that's pretty much as bad as I can put it. Yuney playing defense anywhere is going to be bad and he can't be hidden completely at 1B or a DH so it's going to be an issue. Yuney 3B, Danny SS, Rendon 2B is probably ok. Rendon 3B, Yuney SS, Danny 2B is probably slightly worse. The first one doesn't solve a problem though, and the second one doesn't create one.
If you actually want to solve the problem (problem being Yuney and Danny are both ok players who might be negatives in 2016 and Rendon can't be relied on) you need to do something more than shift to the optimal positions. How about trading for Todd Frazier? That seems like a popular idea. He's good offensively and defensively and under a reasonable contract for two more seasons. Of course that means he won't come cheap and if the Nats won't deal Giolito or Turner or Ross the Nats really don't have anything of value to offer other than bulk.
Oh and I've said it before but I think Stephen Drew will end up being the bench guy. Juan Uribe would be the ideal one for me, but could get starters money somewhere. Given his last few years, "Old Espy" as I'll call Drew for his power/D/nothing else combination, should be cheap. The Nats could do worse (and just did with Uggla!)
Outside the Box Suggestion : Trade Giolito for Arenendo. Pitching prospects are generally questionable. First on whether they can make it, and second on whether they can make an impact. Strasburg was more highly regarded than Giolito and he's been really really good but has gotten the Nats all of home field advantage in one playoff series. So even if Giolito manages to make the majors without suffering another injury and is really good, he's only able to impact the season so much. A great young power hitter though? That's more of a game changer.
Stupid? I'm trying to go outside the box here and there are a couple of things about Giolito that should be addressed. One is that in AA he didn't dominate. In 8 starts he merely did well. Now as a 21 year old in AA "well" translates to "really good" and no one thinks he isn't on a path to a major league rotation, but it does start to question whether he'll be top of the rotation and if so how long it might take for him to get there. Also he's only up to 117 IP. It's likely next year the Nats top him off at 140ish meaning that it's very unlikely he's an impact player for next year's Nats either. The most likely scenario at this instance puts him at having an #3 type season with less than 180 IP in 2017, not even 2016. If you think the Nats fortunes over the next few years are going to be driven by Bryce Harper, understand he could be gone after 2018. Meaning the overlap for great Giolito and prime Bryce might only be a single season. Is that enough to not go all in now for?