Jolteon is way better in-game with a higher speed and special attack then Electrivire. Not only that, but your team is almost all physical attacking Pokemon, so Jolteon is definitly the better choice.
Infernape is far superior to Arcanine in the fact that Arcanine is sort of like a mixed utility, or like a jack of all trades, but Infernape is much better in game for its fast, sweeping atributes. With incredible speed, an acceptable moveset, and good attack AND special attack, Infernape is by far the better choice.
Relevant Topics Concering your Team: Electrivire can have Motor Drive, which brings the whole Jolteon vs. Electrivire debate into question again, because your Gyarados is 4x weak to electric. However, I still stand by my choice because Metagross resists electricity already, Snorlax is a great special tank, (which is useful because most electric moves are special), because Electivire is much harder to obtain, and the reasons I stated in the first paragragh. Also, Arcanine's two main abilities are way better than Infernape's Blaze, but Infernape still outclasses Arcanine by far. (In game, at least.) That's it for now, and have fun grinding for a few million years.