Raid Assault vet 3 airborne have +70% damage, +50% HP, and -20% incoming received accuracy. It was like you were fighting 23 Airborne troopers with 7 Recoilless Rifles between them.
(In other words, about equivalent to 4 vet 0 recoilless squads).
Regardless, a good initial shot with the tiger would have shut them down anyway. Thing hits hard. Veteran Airborne RR squads get 3 or 4 men knocked off them by single Tiger shots all the time.
the RRs were standing in a crater the whole time as well, yellow cover