Before I go here is a quick look at stats of wrecked and fragile players in my league. The sample is small and limited to the stats of my last season completed. Meaning if a injured guy didn't play at all last year and retired he doesn't show up in the sort. It's the best I'm going to do late at night with a golf match in the morning.
Edit: All stats come from a league that uses "modern day realistic" for both long term and short term injuries.
I'm not going to write out all of the data as there will be screen shots at the bottom. The stats include all levels even though filtered to MLB players. This was so I could see the stats for the entire season and not have players have 100 PA at MLB but 300 more at AAA, same thing for pitchers. So the short version..
Fragile batters from my last season.
164 total
156 had at least 100 PA
with 86 of those having at least 400 PA
Wrecked batters
78 total
73 had at least 100 PA
with 33 of those having at least 400 PA
1 had less than 50 PA
Starting Pitchers. These are only current MLB SP though the screen has minors and FA included.
SP that are wrecked
12 total
10 of those threw at least 100 innings.
The 2 that didn't throw 100 went 77.1 and 56.2
Screens are both of wrecked batters and pitchers and you'll see at the top that both minors and FA options are checked. Scope is "all levels', split is last year. Should give a decent look at what I am seeing. Didn't have time to get fragile done too. I do see I messed up the batter screen shot as it's scope is MLB only while the stats above are from a "all levels" scope I used before taking the screen. For clarity it's still the same 78 wrecked batters, and as you can see they got plenty of MLB AB's.
With what I see in my league I don't see the need for me to dig any further. Of course I'd still be happy to look at any data others may post that could end up changing my mind.
I still think if you want Markus and Matt to look into this some type of data is going to be needed. But then I'm not them so that is only my opinion.