Okay, EV training your pokemon will make them a LOT stronger.
You can look up how to EV train and stuff here on this very site if you need.
But for now, I'll just give recommended EV spreads for your pokemon.
EVs: 252 HP / 252 Defense / 4 Sp Defense
Replace Iron Defense with Volt Switch so you can get out of some tricky situations. Especially if you run into Taunt. Red Card is a great item for Sturdy Forretress, but if you can't get your hands on it Leftovers also works well.
Looks great. Recommended EV spread: 252 HP / 252 Atk / 4 Spd
Also, if you haven't already obtained a nature, Adamant would be best.
Or for an alternate approach, EVs could be 252 Atk / 252 Spd / 4 HP and a Jolly nature.
Looks great. No suggestions.
Actually, while I love Eviolite users, because of the Naughty nature, it would be much better to just evolve it.
EVs: 96 Atk / 160 Sp atk / 252 Spd
X-scissor / Megahorn
That will work a lot better for you. It also kills dragons amazingly well.
I would take out Close Combat and Extremespeed for Dark Pulse and Vacuum Wave / Nasty Plot. Your nature will make you naturally stronger using special attacks.
EVs: 252 Sp atk / 252 Spd / 4 Hp
Expert Belt would be a good item as well. More effective than Shell Bell.
Jolteon is already fast enough to not normally need Thunder Wave support.
Volt Switch can help you scout out your opponent's team.
EVs: 252 Sp atk / 252 Spd / 4 HP