Okay my team is
Level 61 Stats- Hp 194
Att. 140
Def. 117
Sp.Atk.-159
Sp Def.-109
Speed-169
Moves: Flamethrower
Earthquake
Dragon Rage
Blast Burn
Level-52 Stats- Hp 161
Attack-98
Defense-100
Sp.Atk-162
Sp.Def-100
Speed-116
Moves: Thunder Wave
Thunder
Detect
Drill Peck
Level 50Stats-Hp 156
Attack-106
Defense-108
Sp.Atk-157
Sp.Def-81
Speed-101
Moves: Fire Spin
Agility
Fire Blast
Flamethrower
Level50stats-Hp 152
Attack-92
Defense-128
Sp.Atk-112
Sp.Def-117
Speed-97
Moves: Mist
Agility
Fly
Ice Beam
Level43stats-Hp 180
Attack-97
Defense-92
Sp.Atk-83
Sp.Def-83
Speed-72
Moves:Surf
Shock Wave
Blizzard
Perish Song

Specifically in FRLG, I have not faced the E4. However, the advice I'm giving is easy to deal with in every game, regardless of the opponent.

You need to consider the types of the E4, and find the best types to field against them (super effective). Your movesets should be able (on one Pokemon) to counter its main weakness should that be a problem [but you'd most likely be playing the advantage ASAP]. The other thing I would mention is to make sure not to double types too much. I understand that the Legendary birds are powerful, but for a Fire-type Poke, I would much rather have your Charizard. That Pokemon is well-trained, and its moveset is exemplary.

That being said, if you wanted to make that a team, you could do it. One question I do have though is why you have two Ice types and two Fire types? I won't even worry about all of the Flying hybrids you have which will be easy pickings for Bruno's Rock-type Pokes.

I would try and get a more average level spread across your team. (Why are you only carrying 5 Pokes on this team?) Train the others to a much more similar level before hitting up the E4.

If you haven't considered the types yet, I would make a suggestion of a Psychic. Or a Grass... (Exeggutor?)

Hope this helps!

AEPMT