Great effort posting but to be honest I don't care what the testing numbers look like: Rowe is not an inside corner. With everything we have seen so far he didn't show the physicality, flexibility or the anticipation to be efficient on the inside.
I think the hope is to run with Gilmore, Butler on the outside and Jones as slot CB with Rowe coming of the bench for specific matchups (e.g. double coverage on #1, ect.). If Jones can get over his mental hiccups I don't think there is anyone else that can push him for that slot position except maybe Jonathan Jones if he has an outstanding camp.
If neither of the Joneses can be trusted then despite everything you say Butler will be the prime player to be send inside. He is clearly a better fit there than Rowe or Gilmore.
All that being said, I love how all of this feels like a luxury problem.
Projecting Rowe as the 5th/6th DB on the field in nickel/dime packages is not equivalent to saying, "he's the slot guy."
The thing is that the 3rd CB in the nickel isn't necessarily "the slot guy" (in the +/- 50% of nickel packages that use a CB rather than Harmon). That 3rd CB often may cover a boundary role to free up
that CB to cover the slot. While Rowe (or CJ, for that matter), may directly cover the inside for specific matchups, he may also come in at RCB while Gilmore drops down and inside.
Similarly, when Harmon comes in for the "Big Nickel", he often replaces Chung while Chung drops inside in a quasi-LB role, and he sometimes covers deep to allow McCourty to drop down closer to the line to man-up on a specific potential pass-catcher.
Also, where the 5th/6th DB lines up (and who that 5th/6th DB
is) likely depends on what type of offensive player Patricia is expecting to line up in the slot - a quick/shifty WR, a TE or an RB.
And pretty much anything can happen in the "dime".
Ryan played RCB almost exclusively last season until Rowe arrived. After that, both Ryan and Rowe were moved around a lot between RCB and some sort of "inside" role that was not necessarily always - for Rowe - to cover a shifty WR. His role appeared to be similar to the way Browner was sometimes used in 2014.
Also, while Rowe may not have been particularly "efficient" on the inside in 2016, he was also learning (on the fly) a brand new set of coverage schemes and field calls - probably more complex than he's played in previously. So there may have been some hesitations on his part that may not be a problem after a full summer and Camp.
Anyway, at this point, I'm still not seeing Butler in the slot on a regular basis as an optimal use of his strengths. Just the opposite. But, we'll see what develops.
My guess is that, aside from McCourty at (primarily) deep safety, Butler (primarily) at LCB and Gilmore (primarily) at RCB, we'll see a lot of mixing and matching in the secondary between week-1 and week-16 (even without any injuries).