Forrest isn't really a striker, he's only got one KO and two TKO's on his record, and that was against sub par competition. The guy doesn't have any real KO power against top level fighters. The only real threat he poses against Chuck is his vicious leg kicks, which are easily defended against.
And we all saw how easily Chuck defended against Jardine's leg-kicks.
I'd roll with Forrest, purely because Liddell is similar to Rampage in respect to checking kicks. Aka, he just doesn't.