I think in many ways your right, but Bruce and other Nobles had a policy of "appeasment" up to a point, they would negotiate with the English and many times give ground in return for lands etc rather than a "full on" battle.

My point was that Wallaces terms were non negotiable, and at Stirling bridge he defeated probably the biggest and most powerful army in the world, whilst being vastly out numbered. wallace proved that the mighty English army wasnt unbeatable. If this hadnt happened I think Bruce would have carried on this policy of appeasement and negociated a kind of Psudeo-independance with Longshanks son, with Bruce as a puppet king.
Instead Bruce took on the English knowing if they could be beaten once they could be beaten again. and at Bannockburn, Wallaces defeat of the English must have been in the minds of those Scots when they lined up against that mighty English army. and in a way the defeat of Wallace at Falkirk must have been in the mind of the English maybe they thought it was going to be easy?

who knows