How many needed to beat Ho-oh?

I would imagine about the same number needed for Lugia (11-12 people bare minimum). I've only done one Ho-oh raid so far, and there were 20 people in the lobby, so we were able to beat it. Surprisingly, even with 20 people, a Solarbeam Ho-oh actually roughed up a majority of my top Pokémon, so if I did it with 10 other people, it could have posed quite a challenge.

It's not much bulkier than moltres, the only issue is SoB. Without it it should be possible comfortably with 4-5

https://www.reddit.com/r/TheSilphRoad/comments/7cobnz/a_more_realistic_suggested_group_size_for_raids/

https://docs.google.com/spreadsheets/d/1ZuudFLchFZWI3lgJf-I7K1HNdlkjVB8ubpzSZ7H9i9M/copy

Minimum 3
Realistic 6
Casual 9

I did it with a group of 17, and we won with 200 seconds remaining.

Solar Beam Ho-oh
8 players, I didn't check levels but they all came for it no random walk-ins, so probably level >35 for most of them
we got it for 40sec to go, it killed 9 of my pokemons
So I guess 7 good players minimum for SoB Ho-oh

Around 5...depending on the group.
It will be done with 2-3...4 will be fairly common.

If you have a couple of lower levels, maybe 6 - we have done 6 and 7 with everyone mid to high 30s, with loads of time to spare.

Used twelve mostly higher leveled players and only used about half the time on the clock.

I did I did a Steel Wing/Solar Beam with 8 with about 50 seconds left on the clock. It was fairly brutal — I think Lugia with hydropump needs to be considered as a tank option for that moveset. I threw in a couple Golems to see if I could get a burst of high-DPS before they fainted, but they couldn't get a stone edge out before solar beam put them under.

For the second squad, I max-revived my two powered-up Raikous and my Zapdos and left the last three slots, including a Lugia, as the game's suggestions. If you want to get more than a couple charge moves out for each Mon, you're going to need a tank.

4+ most moves (it was possible to 3 man moltress but not really 4 most players)
7+ for solar beam

So, we just made 2 Ho-oh Raids in a row.
We all were between Lvl 37 and 40 and managed to beat them with 6 Accounts, with around half the time left.
The first one had Fire Storm, the second Brave Bird as charged attack.
Just Keep in mind, that Ho-oh flies very close, so you even have to throw a curved ball pretty straight to hit the center and therefor get a great or excellent.
Sadly both ran away, one of them with 2210 CP (maybe 96% IV) :S

Don't even bring SE golem to fight SoB HooH. I can't even fire one.