It's all very well saying that Mitchley and Brooke just need game time. There's a reason they don't get on the pitch very often...
LS probably realises that he can't trust them to play at the level required, Brooke gave us a bad 10 minutes on Sunday although inmitigation he was alright at Harrogate and Gainsborough.
If our 3rd striker was Chris Senior for example (and I'm not starting anything here, I'm just using him as an example of a player who we've all seen and know his capabilities so you know the standard of player I mean) he'd get brought on quite often for the last half hour for Lawrie/Reeves. You wouldn't be looking around for Richman to come on so you could shove Dunc up front. So he wouldn't be rusty/out of nick/in need of a goal/disillusioned by this stage of the season.
They just haven't been good signings. A lack of good local contacts from LS? Possibly but thank God Reevesy came back, these two were our starting strike pairing in July!!