I think these are good counters, but the other important thing to do is talk about optimal moveset and then quantity.
Interesting things on your list:
Machamp appears 3 times in the highest tier
Rhydon is 1 or 2 on a lot of those counters
Grass counters can serve dual purpose to countering a lot of raid bosses too (Eggy/Venusaur)
Tyranitar is very valuable but the other substitute is an issue.
Thank goodness for the Eevee trio.
Counter to Raid Bosses
Boss. Counter.
Arcanine. Rhydon MS/SE
Alakazam. Tyra B/C
Machamp. Alakazam PC/FS
Gengar. Tyra B/C
Vape. Egg BS/SoB
Jolt. Rhydon MS/EQ
Flareon. Golem RT/SE
Venu. Charizard FS/OH
Charizard. Golem RT/SE
Blastoise. Jolt TS/TB
Rhydon. Venusaur VW/SoB
Lapras. Machamp C/DP
Snorlax. Machamp C/DP
Tyra. Machamp C/DP
This is based on a combination of pokebattler and GP. Anyone have thoughts on this and maybe other max counters?
Answers
Rhydon has higher Attack stat than Golem and tankier. I think Charizard is slightly better than Flareon for raids due to being tankier. Selecting mons for raids is slightly different than normal gyms.
These counters seem optimal for raids with minimal amount of trainers. Of course if there are 20 trainers in a raid then mons and movesets don't matter. Raid counters and movesets should be selected based on the highest DPS, no dodging except maybe a few charge moves, combo of STAB and SE, without fainting all 6 attackers, and without the need to quit for revive/potion mid battle. Potion efficiency goes out the window on Raids - a complete opposite to normal gym battles. To get that damage and team bonus I think this is the optimal strategy especially when short handed.
my experience soloing lvl 3 raid bosses is that I don't want tankier, I want highest DPS. And double rock Golem is better than Rhydon vs. fire types, so I still stand my opinion that your Rhydon is top 3, right after 2 golems (also EQ Golem is above).
But I might be wrong if your Rhydon is able to fire one extra Charge move due to tankines.
Unfortunately the current raid version of pokebattler feel way wrong from my point of view (based on results from there you cannot solo an Arcanine, more than 200 seconds for each counter at lvl 38.5, while myself and a lot others did that) so I cannot use it for analysis. But yes, there Rhydon and even ground version of Golem was on top of my rock ones :).