Why not split the section up into two vehicles? You could have a smaller, lighter vehicle, more room for auxilaries like medics and dog handlers, and if each vehicle had a robotic gun turret, you'd be adding additional firepower.
Cost, span of control, lack of protection (a big no-no for the government) and sustainment. Twice the vehicles, twice the fuel, parts, etc... required which now increases the size of your A and B echelons significantly.
In the Army things, generally work best in packets of three or four, any larger than that and it becomes two cumbersome for one person to manage. The problem with LAV 6.0 is that we've taken an IFV and tried to also make it an MRAP (given it a V-Shaped Hull, added blast protection, added special seats with three point harnesses designed to cushion soldiers from a blast). There have also been calls to remove the turret and put an RWS on it because a couple of soldiers got killed in rollovers, etc.
We've greatly increased the weight of the original hull which has altered it's off-road performance and also made it far less mobile. Putting an RWS on the hull to prevent death from rollovers is also a false savings because we need to think of how many lives the decisive firepower of the 25mm has saved. I can think of a number of engagements, where without the 25mm, things may have turned out a lot differently. In his book, "Dancing with the Dushman", Col Hope refers specifically to the combat power of the LAV III 25mm being the decisive weapon in his engagements with the Taliban.
What the Army needs to do is lose the infatuation with sexy and go with the tried, tested and true. We need to standardize equipment across the CAF and if that means buying a vehicle that's a little cheaper, so be it. I personally think we are too reliant on vehicles and we need to make significant investment in more man-portable systems i.e. AT Weapons, MANPADs, Mortars, etc...
I would much rather have a platoon of LAV IIIs that carry some light mortars and anti-tank weapons with them than a bunch of LAV 6.0 with nothing in them. At the end of the day, it's all about layering of effects to provide the maximum amount of counters to what your enemy has at his disposal.