Again I'll point out you don't leave two in the middle against Pulis , especially if one is the lumbersome Livermore . Pulis would have had 4 in the middle before Field sat down.
When Assombalonga came on Boro changed their formation and went to a 442 so there was no need whatsoever to have Barry, Livermore and Harper in midfield against them. Plus Brunt is more of a liability than an asset in midfield anyway. I also agree that Livermore is clumbersome but Moore choose to bring him on for Barry who is clearly our best and most consistent central midfielder. Boro were at their most vulnerable defensively and Montero down the left could have capitalised on their tired legs, especially with Gayle given 10 minutes in the middle.
I like Moore but he got his game management and subs all wrong today and the clanger from Brunt wasn't out of keeping with him this season, you didn't need to be mystic meg to realise him and Livermore had potential to backfire.