Personally I've always thought a staff would do well to have guys who throw from different angles, with different strengths, different deliveries, etc. After all, if one guy is getting shelled on day, would you want to replace him with a relieve who looks exactly the same?
But there are many who believe strongly in what they do, and they feel like if one guy is getting pummeled, it's not so much about his style as his failure to execute. So they do indeed turn next to another guy who looks a lot alike. Stick to the game plan, seek better execution.
And some go so far as to make over their recruits in the image they have in mind. Those who adapt to the school's style have a shot at getting innings. Those who don't, don't, and often sit the bench or transfer.
The latter approach doesn't always work out so well for an individual player, but I've seen programs have great team success in this manner. A recruit should know going in what the philosophy of the program is and how he fits, or doesn't fit/will be asked to adapt.