This is true but it is one of the odd things about football that having a great goalscorer as the focal point doesn't always make the team better. Utd at the time were all about the variation in attack, goals and creativity coming from everywhere, and Cole was a huge part of that, could drop into and be more effective in different spaces than those huge names, formed excellent partnerships with pretty much every forward he played with other than Cantona and had an unselfish, team first mentality.
Shearer and Batistuta come in and suddenly a large portion of the attacks are funneled towards them, the team becomes more predictable, we saw this gradually with RVN, and yes there were other elements in play, start of transition, in make up of the team and guys like Giggs and Scholes changing their game but a more rounded attack is always the better option in my opinion. What Shearer and co would give is match winning moments in big games but I am far from certain that the team would have been better or scored more goals over a season.
Building around guys like Cantona and Ronnie is a different thing to Shearer/Batistuta and RVN, the first 2 offered much more than goals alone.