Level 20 Rhyperior (Smack Down/Rock Wrecker) deal 22.5 DPS
Level 40 Reshiram (Fire Fang/Overheat) deal 21.8 DPS
Don’t use fire attacker at all and a duo really isn’t that hard with level 30+ rock attackers. Most people should have at RR rhyperior since CD was from earlier this year. If you only have 4 of those at level 30+, just go in with the 4 and max revive them. Don’t fill your team with non-rock attackers.
I made this spreadsheet below for my community, please ignore any typos or errors as i made this very quick and did this without getting paid .The columns in yellow highlights are players needed to beat Mega Pidgeot or articuno at certain level, assuming all are using the same pokemon at the same level through the raid. For example, if all players use level 30 rhyperior, it takes 1.9 players to take down Articuno in 300 seconds. 1.9 means it’s a close duo, where something like 1.3 would be an easy duo.
A little more info on these spreadsheets - Before GBL existed, my only fun in this game was to do short man raids as challenge. People in my community is always asking “how many are needed to beat” the T5 bosses, so i started making these spreadsheets for them. T5 raids are 300 seconds and boss’ hp is always 15,000. I took out 30 seconds for relobbying, pokemon fainting, game glitching. So [15,000HP divide 270 seconds] get you 55.55 DPS needed to take down a T5 boss. When you build your team, try to average out your DPS. If it can go above 56 DPS, it is almost guaranteed to take down the boss unless the game crashed at some point. If your DPS under but close (50-55 DPS), there is still a chance but you will need some RNG luck.
Disclaimer: I just take DPS from the website i forwarded from the link above. The 10% friend boost and 20% weather boost was a straight multiplication of 1.10 and 1.20 of level 40 DPS. I did not take Break/Bulk point into account. I honestly did this to save time, so it is not 100% accurate all the time.
Hope this helps!