He was averaging 88 for WA. If he goes back he’ll pile on plenty of runs in shield cricket.
He got a couple of good balls in Melbourne and is doing as well as anyone else this series.
Stop using his Shield runs as a basis for selection, he's played enough Tests now for us to see what his output is going to look like, at best it's one big score amongst a string of single figure scores OR it's a bunch of starts. He's never going to be consistent at this level regardless of if he's hitting runs for WA.
Also find it odd that you seem to think he has issues in spinning conditions and aside from that he's great. You don't seem to understand Shaun Marsh at all, he has hit runs in all conditions including South Africa and Sri Lanka. His issue is it's always a flash in the pan and he can never put together a string of good form (unless it's against genuinely inept bowling like against England last year).
I'd hate to think it's state bias causing you to defend him but the bloke has absolutely nothing to offer us in England, especially when collapses against the swinging ball are our main issue and he's the worst starter we have. I would rather even Head or Labuschagne in the middle order at this point, get Marsh out of the Test team so he can start focusing on short form cricket for this years World Cup, that should be the last of him at International level.