Well as I understood it, your post said that our players are not very good, Sheehan understands this and that's why he set them up to play "ugly" football against Derby.
The Plymouth game showed that Sheehan is perfectly capable of setting his players up to play 'champagne football'. First manager we have had since Laudrup who both attempts to moderate his tactics according to the opposition and does it well (as I posted recently, Carvalhal tried but obviously did not succeed). Maybe I'm being a bit harsh on Potter. But Martin and Williams really only had one game plan, Cooper had several but kept sticking to each one for multiple games in a row even when they were no longer delivering, and I am not sure what Duff thought he was doing.
Anyway, the squad isn't perfect but I think you do them a disservice. There's talent there to build on.