I have been using WS4SB in conjunction of my Karate training and it has been working well for me.
If you ask my to come up with a WS4SubmissionFighter routine (LOL) based on WS4SB I would make the following changes:
1) On Upper body ME lift, max out on a pull lift instead of a push lift
2) On push supp lifts, spend more time on floor press variations rather than bench
3) On pull supp lifts, spend some time on isomatric e.g. seated cable row, hold on "top" for 60secs
4) Your grip training will be more important than a football player and/or a striker, so train ALL kind of grips
5) Train your abs in both prone and supine position
6) No, you don't have to train in a 4-day split.
Martin Rooney mentioned in his "Training for Warriors" book and DVD that if one has about 4-5 or more of hard skill training per week, then one should only train twice in wgt room and should focus on strength i.e. 1 upper body strength day, 1 lower body strength day or 2 full body strength days.
Just my 2cents and I hope it helps.