The convair "tests" also occured during some of the wetest seasons on record. I am sure they were able to demonstrate their capabilities in full sitting on the ramp with no fires to fight.
Also the remark about SEATs "flying in the face" of the large tankers / scoopers refers to the idea that there is some kind of competition. What you don't seem to understand is that these aircraft work together in a bigger picture and here in Australia we are missing a large piece of the puzzle.
While we can do without the heavy equipment in most situations, when they are needed they are an invaluable tool that we are missing.
Cheers
DW