This really depends on the mission and your ship. Some of these are easy enough to beat with just a solo FDL/Chieftain. Some are extremely dangerous even for a Hull/Shield tanking beast. I took my fully engineered Corvette (which had never needed SCBs before, even vs swarm waves of police) into a wing assassination mission solo thinking it would be cake. But I a few short seconds later, was facing a Rebuy screen. Went back for a second attempt, and the NPCs killed me even faster! Third attempt and swapped out some cargo and SRV pods for more HRPs MRPs and a crucial SCB. I *barely* survived the third attempt, and had to flee before being able to kill the Target. On the fourth and final attempt, was able to just barely kill the Target Cutter and escape with a limping ship.
I am one of the better pilots in the game and can hold my own in 1v1 PVP vs all but the best CMDRs in the game. Even though the game seems to scale the difficulty compared to your ship/skill level, I would recommend that newer to middling players bring at least one friend on these wing assassination missions, just in case you hit a "difficulty spike" like I did