The Airspray job isn't air attack; it's a SEAT (single engine air tanker) position, and the minimums expressed are OAS/OAM pilot carding requirements. Thats what the government provides as the minimum to be issued a card. Competitive or that position is closer to 10,000 to 25,000 hours experience, and likely most applicants will have closer to 10-25 years of experience, much of it in the AT-802. It is not an entry level job.
The job cites the NAFA-1 and NAFA-2 schools; these are the national aerial firefighting academy (formerly SEAT academy for single engine operations); these schools can't be attended privately, and must be done under the sponsorship of an employer (one must already be a SEAT pilot to go or to have gone).
SEAT operations do everything that heavy tankers do, and are often used in places that heavy tankers can't go or fit. Think carefully about flying a heavily loaded single engine airplane in wind and turbulence and low visibility into tall, steep terrain in low visibility on forest fires in high-traffic areas.