Bingo!
The 'attending every incident' could be tolerated, or even helpful, if it were in alphaone's context, but the fact that they assume command every time means that no brigade officers get experience in running an incident.
At the recent captain's seminar run by the region (where this topic seemed to be fairly common across a number of groups), it was suggested that small proceedural adherences could affect this - first arriving officer refer to themself as 'incident controller' on the grn. That assumes that comms calls the 'incident controller', not the most senior person on the scene (as seems to be default), and therefore requires a degree of formality in changing the incident controller. However it is largely irrelevant as the GO or DGOs are usually first on scene anyway.
It will come to a head shortly when someone retires and the complaint pops up 'but there's no one experienced enough to replace them'.
RescueHazmat makes a good point; why do they attend so many incidents?
Do they have no faith in the brigade officers? Do they like the excitement of lights and sirens?
In anwer to your simple question; yes. Why would two DGOs respond to an incident to which they only page one truck, and is suspected to be a false alarm?
I suspect the question has never been posed; 'why do you attend all incidents' and worked through, rather I can imagine the approach would (if at all) have been a little more direct.