Best of luck, Chef, but to be honest I don't see why this stat is of interest.
Why would horses who ran on the flat at this track be unable to win here in Jan or Feb? Unless you can come up with an adequate explanation I would think it best to ignore it.
My guess is the ground is very testing at Carlisle at this time of year, and it's a stiff track anyway. Therefore stamina is vital, and many ex flat horses are not strong in that department.
I think your bet will succeed, but for not quite the right reason. High Ransom was a stayer on the flat and the trip today should be, if anything, a bit on the short side for him. On the other hand a look at the progeny stats for Red Ransom shows a clear aversion to heavy ground. The slower the ground the less often they win.