Machamp solo
Answers
The only thing that might hold you back is the Ho-Oh. If it was level 30, I'd say you'd be fine, since the other attackers should get you ahead of the clock, but at level 20, the Ho-Oh is not going to put out much damage. Do you have an ES/FS or ES/SA Lugia, or a DT/H Dragonite you can put in place of the Ho-Oh? Or even a powered up DT/O Dragonite?
ES/BB Ho-Oh is respectable as a tank anchor against Machamp, but it's not stellar. And with it only being at level 20, I have to believe you have better options to round out your team. Good luck.
I suspect the Ho-Oh is there as insurance against BP/HS Machamp. BP/HS shreds the psychics who don't resist either attack, and HS is spammed as often as DP. I agree with Scooter though that you should power up Ho-Oh. Even with that big CP, he's not that strong of an attacker (and, sorry to say, 2149 isn't that strong of a Ho-Oh) and needs all the help he can get.
Your team look great, I think that the only way that be sure is made the raid.
I have a similar team
2386 CP Alakazam PC/FS
2509 CP Espeon ZH/FS
2509 CP Espeon ZH/PB
3351CP Mewtwo PC/SB
3100 CP Dragonite DT/H
2759 CP Ho-oh E/BB
I'm still not tested it because i have not found a machamp raid but as soon as I find one I will make it.
In the worst case you will lose like me against Alacazam :) (I need more tyranitars)
Just do it and then tell us what happend
If you have even 1 Fast TM, you might want to use it one your Confusion Alakazam. Zams are so glassy and it's so hard to dodge with confusion that Psycho Cut is really the preferred move, also will charge your charge move faster. And if it doesn't manage 2 Future Sights at the minimum, it won't really be pulling its weight.
No. For Machamp raids, you want confusion. The difference in damage between the two quick moves is huge, and you shouldn't be dodging very much in a Machamp raid, like no more than once per attacker. If a confusion Alakazam gets off a single FS, it will be carrying its weight. If it gets off two, it will be a superstar. If a PC 'Zam gets off two FS, it will about equal the confusion 'Zam landing one FS.
PC is more user-friendly and easy to use, but it lags confusion badly in DPS. The only situation where PC is really better is in gym battles if you choose to dodge everything (i.e. quick moves as well as charge moves). If you only dodge charge moves, confusion works and is much better. For raids, where you want to keep dodging to a minimum, it isn't even close.
If you say so, but with both my Zams (2 PC/FS) and Espys (2 Confusion, 1 ZH), if I miss dodging more than one or two charges I need to rely on my DT/H Dnite to finish the fight. Otherwise my dragon never touches the field. And I personally find the superior energy gain far more important for glass cannons.
That is the thing about Zam though, afaik, there isn't another mon whose quick moves are of the same STAB typing and so different as to be that much more ideal (or at least make debate on the topic make sense) to dodging and non-dodging playstyles.
Edit: Mewtwo not withstanding
Gengar sort of falls into that category, even though the damage done by shadow claw and hex are similar. SC is much faster, and therefore has much higher DPS, but hex builds energy much faster. The overwhelming majority of the time, SC is better, but not always, even given the same IV's. Yet, people continue to spout the urban myth that a 0% SC/SB is always better than a 100% H/SB.
That's quite interesting, especially since in that scenario the quicker move does a bit more damage but with less energy gain, as opposed to Zam where it's the other way around. I have 3 mid 80 IV SC gengars and 1 perfect Hex gengar, but I've never used the perfect and haven't used the others since lugia was a raid boss, so I'm unfamiliar with how the moves truly compare.