In general, I actually think it's a good idea. The caveat is, as others have stated, you need transaction flexibility. Also, this assumes your core skill line up is set, with one or two key handcuffs and QB1. Granted DSTs are heard to predict but you can turn that thinking around and argue than why stick with one. If you are lucky enough to pick up DSTs that play the turnover factories (Jets, Jags, or rookie QB/debuts, etc) then go for it. At least you've got trends on your side.
Now specifically, IMO to the OP, your line-up lacks enough RB fiber to allow for tying up those rosters for DST. J. Bell, Mason and Blount aren't the most solid bunch. Your WRs may compensate for the weak RB production but other moves may be in the offing.