For EV Training, it depends on what you want to use a specific Pokemon for. It doesn't matter if a Pokemon is a Legendary or not to be stronger than the other.
Your Typhlosion maybe stronger than your Entei due to it's Nature, IV's and EV's.
Only you can decide on which Pokemon should be replaced with Suicune, but I would replace Entei with Suicune.
Edit:
Lugia is mainly a Special Attacker, so you can EV Train its Sp. Atk and Sp. Def along side its Speed.
Typlosion is a Special Attacker as well, so EV Train its Sp. Atk, Sp. Def, Def and Speed.
Dragonite varies as it can do many things, so do whatever you want with it.
Raikou is a Special Attacker, so EV Train its Sp. Atk, Def and Speed.
Suicune is a Defender, so EV Train its HP, Sp. Def, and Speed.
Gyarados is a Physical Attacker, so EV Train its Atk, Sp. Def and Speed.
You should have a look at Smogon