WTF? He only has to spend the normal deposit transaction to position his SH at a desired ordered choice among the available choices given by your function.
Ok, since I really have no idea what argument you are making, let us make this really basic:
1. Imagine there are 10 SHs.
2. Imagine evilguy controls TB number 10, the consensus point.
3. Evilguy adds another SH via a deposit tx during his TB.
4. The SH randomization function is (Put new SH at end of list)
5. There are now 10 SHs in the exact order as before, plus evilguy's second SH at TB 11.
6.

7. Evilguy controls the network
Can you please fill in part 6 for me?
If you control all the TBs, you control what goes in the consensus (as well as getting all the tx fees).
Oh hey look, more ideas from some other design that AnonyMint has in his head that can be attacked, because there just
must be a way to attack it, and if the design doesn't have an attack, then we'll add to the design so that it does. You are unbelievably immature.
No one should pay any attention whatsoever to anything you have to say. You are some kind of sociopath.