I'll slash it.
Jabba, thank you for finally posting in here. As I said, Pokemon that cannot threaten you are out of the picture, as are Pokemon that need freaky specialized sets. Straight up, that means Special Lucario, Non-PHazing Zapdos, non-Specs Zone and Jolt, Special Electivire, Rotom, Breloom. The result is that you have the following:
Infernape
Swampert
Lucario
Machamp
Kingdra
Heracross
Infernape is frail and can be hit before it forces you out, and if you don't have a way to beat it you're boned regardless.
Machamp is slow and can be beaten by other members of your team.
I talked Lucario over with Darkie and as long as it doesn't have a boost it will lose to you unless you start at 75% or less.
Kingdra deals 37.38% - 44.06% with Adamant Life Orb Waterfall, while you deal 39.86% - 47.08% with +1 Thunderbolt and can beat it if you Sub on the switch and CM as it breaks your sub. If it DDs as you CM, then you can still beat it.
Heracross takes 48.84% - 57.81% from +1 Flash Cannon before Close Combat (73.09% - 86.71% after). If it uses Megahorn it can miss, and Close Combat lowers defense. Both deal 51.98% - 61.14% You can dent Scarf sets and CB sets if you wish, or simply get the hell out of dodge.
All of these Pokemon pose threats to Jirachi, but none have reliable recovery, meaning their lifespan is limited.
All in all, the two are kinda equal. Latias necessitates the use of Flash Cannon, though, which kinda hurts Psychic's viability as main STAB. I'll slash Psychic in, as it really is viable.
I'll change it to
CM
Sub
Flash Cannon / Psychic
Thunderbolt / Signal Beam
Psychic/Signal Beam does give pretty cool coverage, but Flash Cannon / Thunderbolt is still better for hitting Steel-types, especially Heatran and Skarmory.