Sure... a hit is not always a kill. Somwhere there was a document arount about downed aircraft in 1999... one of the MiG-29 got hit 3 times and was still flying.. Another one got hit but crashed because the pilot was tiered at the final.... So.. 1 hit 1 Kill can be, but do not calculate with it. For big planes like a SU-27 or similar I would in gerneral calculate 3 missiles for 1 jet. Lucky if needed less, but.. maybe 1 misses, the second one just causes light damage..
Cupra's post in Is that possible to survive AMRAAM hit? was marked as the answer