Psychic attackers are most useful for soloing Machamp (and Gengar).
How many of your Alakazams (and Espeon) have all of the following:
a) Good moves (Future Sight is recommended)
b) High level (around 30 is recommended)
c) High IVs (wonder for Mystic, amazing for Valor)
Other good attackers for soloing Machamp are Dragonite with Hurricane and Gardevoir with Confusion + Dazzling Gleam (or Shadow Ball).
As for soloing Gengar, Tyranitar (Bite + Crunch), Houndoom (Snarl + Foul Play or Crunch) and Gengar itself (Shadow Claw or Hex + Shadow Ball) are suitable (of course, they need to be level 30).
If you already have a good Machamp (and Gengar) solo team, then no point investing Rare Candy into Lugia, unless potions are always scarce and you need Lugia for Potion Efficient Gyming.