I FINALLY DID IT !
And well, all what i can say is : Screw Myrmidon and Trebuchets.
Although they seem to work fine first, i couldn't make the mission with them.
Here's the Loadout i used : (well it was in very easy mode ><)
Alpha Wing with Perseus, Kayser & Prometheus, 5 Trebs 5 Silettos
Beta Wing Hercules MkII with huh.... anti-fighter things. I didn't think about em much.
Gamma Wing using.... i don't remember at all oO'
Actually, the Trebs are not usefull at all.
Just one thing to say: GET SILLETOES !
Whereas the Treb takes 5 Shots to hit 3 times, and 3 shots to kill a cannon, the Silletos are much more effective
Instead of firing Trebs at 5000 range, just go near 1500 range and fire silletos to one shot the beam cannons.
And since the Trebs are really slow and uneffective, it'll be even faster this way.
Just remember to aim carefully, Silletoes guiding isn't as good as the Treb one..
You may think i'm stupid but uh, here's what happened to me for now :
- First, i couldn't make the mission without dieing (most of times) using Myrmidon & Hercules. With the Perseus everything is just fine, i ended the mission with 92% integrity (without rellying on shields much)
- I went to attack the Ravana with 3 trebs and 3 Silletos. I fired my Trebs at one beam cannon. Only 2 hit the target, and the beam was at ~10%. Then well... i just took my 3 Silletos, and one shot all the 3 beams.
Anyway, good luck to other people doing that mission