Not exactly viable. If Crobat is to stall-break, the above set is the best bet, as it deals with stall much more easily.
That's true if you want Crobat to be the best stall-breaker a Crobat can possibly be. However, the build I've presented is meant to make my Crobat the
best fit for my team that she can be, and I need a strong Poison-type move. In addition, simply having Taunt on a Pokemon that fast can be extremely useful. I would argue that my build is
more viable in this instance, because it takes into account the team that the Crobat is part of.
Now, the exact details of my Crobat may not have a whole lot to do with helping the OP make his team better, but the general principle here does. We may have to agree to disagree, but I don't believe there to be a single best build for a Pokemon, only builds that are more appropriate or less appropriate for a given situation.
It may be the case that the OP's team is best served by a bulky stall-breaker Crobat. But he could go a long way towards making the team more well-rounded by simply swapping Confuse Ray for Taunt.