Are some cases in this kind of missions you need to kill the target in under 1 minute, that is - the time your shields can resist. I got one like the OP here with a "venerable general" in a ship made of Duracell batteries, guarded by 4-5 buddies ( a Chieff, a pair of Vultures, and 1 - 2 Mambas ) PLUS a bunch of syst auth. ships ( some 4-5 of them, but with more 3-4 reinforcements in 1 minute after the first shot fired ! )
My first try, in a tank build Vette, was a spectacular failure - I didn't run away on time ! - so I meet the rebuy screen ...

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The target is legit in the system, so the authority vessels will jump on you immediately, since they are always there, at 3-5 km of the target. My Vette shields melted in 4-5 minutes - at least 4-5 guys where shooting rails and plasma at me, and the other dozen with lasers and missiles ...
Second and third time I run on time - but with hull damage, once heavy one ( hull at 25 % ! )
I give up my Vette, and take my FdL - a huge Beam and all others MCs !
First run I manage to get the target at 20 % health before my shields dropped - so I made an escape to save my ship.
Second run on FdL I manage to stick in his tail, at 3-400m, for some 30-40 sec - and I killed him in under a minute - then I run away, with shields at over 1/3 , all that after 10-12 other NPC.s ships did the best they could to stop me !
FdL is like a precision, surgical weapon - fast and without collateral damage ! Probably THE best ship for individual assassination missions; Mine have some 2800 shields, and is more than enough to endure concentrated fire from a dozen of NPC for more than a minute...