I thought Charlton Thompson had a great article and I agree with his point that you can't have a specialist unless he's the best in the league. Each roster spot becomes too valuable as the Texans improve each year.
I would go a step further and make a radical suggestion ... why not do what you planned all along ... have Domanick Davis as a returner. The first couple of plays after a return could then be handled by Tony Hollings, who you want to carry the ball 15-18 times anyway. You could say you risk injury, but you risk injury on every play anyway and don't forget that a returner is putting up 1500+ yards a season. The Texans sort of tried this last year with Hollings returning kicks, but Hollings isn't a returner and Davis is. If you're a giraffe ... be a giraffe.
Two extremely valuable things are return yards and roster spots. Remember, last year the Texans couldn't give Petey (Faggins) a roster spot coming out of camp. Fortunately, he wasn't claimed and made it to the Texans' practice squad, but what if he had been. We would have lost our future 3rd CB.
Creating an additional roster spot, without losing competence in the return game is huge! It may allow the Texans to keep a player from being claimed, like Jamaal Lord, Sloan Thomas, Kendral Starling, Charlie Anderson ...