On what basis? We did okay with our current level of pace surely?
I think pace is definitely needed. This year we haven't really needed it because most teams have shown us an enormous amount of respect and sat quite deep leaving no space for pacey players. This season our attack has been mainly focused on using the creativity of players to unlock defences. I can think of several occasions this season where teams have come to Sixfields and camped with 10 men behind the ball to frustrate us. I anticipate that next year will be different. I envisage a lot more teams pushing up and pressing higher but ultimately leaving the space in behind. It will be vital that we have the pace to exploit this.
Combine that with the fact that players generally (not always) tend to be quicker the further up the leagues you go, added pace is a must.