IF you tried to run Manchester Victoria with just 2 through platforms, what would happen?
This model assumes no trains terminate, and TPE are not allowed their long dwells. Any terminating trains from the west get pushed out to either Rochdale, Stalybridge, or get tacked onto existing eastbound trains.
RTT suggests very few terminating trains in the next hour, only one from Leeds seems to terminate on 5, but presumably could terminate on 1 if needed.
So, move Victoria to a 2-platform operation and then look at the EMU services. The target is 4tph to come from the Airport, via Castlefield, and use platforms 3 and 4 at Victoria to reverse back out to Liverpool/Wigan/Preston. These two, plus the 2 eastbound become 6tph via Castlefield and the Ordsall Curve. By removing the Southport and the Blackpool North trains there are less conflicts.
If the TPE to Liverpool via Warrington Central does not fit then put that back in the main shed.
For completeness, the TfW runs through Victoria (I believe you could possibly turn around and make the path back to save a unit) and onwards somewhere to reverse.
That leaves Castlefield with
2 x Oxford Road to Liverpool via Warrington Central
1 x Piccadilly to Liverpool via Warrington Central (EMR)
1 x Piccadilly to Liverpool via Warrington Central (TPE)
1 x Piccadilly to Scotland via Preston
1 x Piccadilly to Lakes via Preston
2 x Piccadilly to Victoria and East
4 x Piccadilly to Victoria and West (Liverpool, Wigan, Blackpool +)
Trains removed
1 x Liverpool via Chat Moss
1 x TfW
1 x Blackpool North
1 x Southport
So I have left the same number of trains on Castlefield, but there is now a metro service from the Airport to Victoria calling at all stops. Nothing is coming from the Chat Moss directly to Deansgate and only 2 trains per hour are coming from Salford Crescent directly to Deansgate. That should mean a lot less conflicts.