Alakazam still worth it?

Personally, if I had two strong Alakazams, like you do, I would save my dust for something else. If you have those two Zams alongside a combination of Espeon, Hurricane Dragonite, double psychic Exeggutor and Shadowball Gengar you should probably be golden for soloing Machamp.

An Alakazam with good IV's will be always worth it. I always use my perfect one when I'm running out of time and I need to do a lot of damage in raids, specially machamps as you said.