@ Oggy85 the shields on the FAS are level 4 enhanced low power mod on 5C bi-weave with 2 level 3 resistance augmented shield boosters, they have almost the same strength (around 200 MJ) but have a higher regen rate and with the boosters are a lot tougher but they will go down so the upgraded hull soaks up the damage.
I didn't get a great roll on the shields so they're towards the bottom of the performance range
but even with stock weapons this is a tough ship and level 3 thrusters allow you to escape from just about anything.
I've tried FDL builds with very high shield strengths but when they finally go down you need to go back to the station for recharging as the rebuild/regen times are significant (around 6 and 15 minutes with 4 boosters on a 5A), I've a Python build with a similar shield/booster arrangement to the FAS and it works rather well as it has around 500 MJ pre modding.