I'm very interested to know too.
In reference to the description of containment as a tactic; when it comes to TTPs, the mission of CFR is fairly simple: utilize suppression assets to either 1. Provide for an egress path out of the aircraft for survivors, or 2. Provide a rescue path for FFs to go in and extract those who aren't able to perform item #1. To that regard, actually putting the whole fire out is secondary to rescue; a close second, mind you, but secondary. Of course, this does have to do with larger aircraft and a fire involvement to a degree where spending precious resources fighting the actual fire, will take away from the 2 items I mentioned above. CFR trucks pump at a rate where their onboard supply is depleted in about 1-2 minutes, depending on gallonage and flow rate, and it takes time for the nurse tenders to get setup to replenish the primary CFR vehicles. That's why you see the tactics exercised in the way they are where it appears that its "only" containment.
That said, every CFR department trains in what tactics to use for different sized airframes, and every CFR department knows that flexibility is key (or should know). Every accident is responded to with haste consistent with safe arrival of the assets to the scene (more than one of these high-CG CFR trucks has suffered an accidental rollover during a hasty response to an aircraft emergency). BL is, a judgement call will always be made as to whether any post-crash fire can hit fast and put out with the supplies available prior to replenishment, or whether the above described tactics of supporting rescue first, and full suppression secondary, is more appropriate.
At an airshow, you can have "backup" or secondary trucks at the station, where the crews are lounging or watching the show or whatnot. However, those would be the structural trucks/crews, as well as the crash trucks which are designated as second-due to a call. That's no issue, and no problem; no different than day to day ops. However, there must still be a first due, and in this case of non-standard flying operations and most especially an airshow, that first due.......at least a rescue truck, and one or two crash trucks........should be posted up somewhere near show center, close enough to have an immediate response, yet not so close as to impede views of the crowd (this is fairly easy to do). While those crews don't necessarily need to be in full ready gear in its entirety, they need to at least be partially bunkered out, to the point where they can easily complete it enroute to the scene and be able to deploy at the ready once handline or rescue operations begin, depending on which unit they're assigned to.
The FAA standard (accepted standard) for CFR response on any airport where CFR is required (not required at all civil fields, only fields with scheduled or unscheduled air carrier service meeting certain pax numbers), is within 3 minutes, the first vehicle capable of fire suppression operations must be able to reach the midpoint of the furthest runway from the station. Hence why at larger airports, there are multiple stations. Within 4 minutes, supporting or second-due CFR vehicles are required to be arriving at the same point.
Why the response took as long as it did at SUU, I don't have that information yet. In that regard, my concern with this one isn't the tactical planning or ops on scene, it's the strategic planning or apparent lack thereof.