I have kept flames in the past; I had one which almost made it 2 years, then he contracted a bacterial infection which was his demise. I'm not sure how that happened either; there had been no new fish additions in quite sometime; nothing else was affected.
I have some wrasses now which I've kept around 3 years.
Out of the 30 wrasses in my DT, 20 are fairy or flashers. Some are over 2 yrs in my care, 2 are over 3yrs.
I have lost 2 out of 4 Flames... Both times it was the biggest/oldest male.
I, personally, prefer to buy the cheaper female wrasses...they always turn male, and most of the males seem to display for any type of female (they get that from me), so pairs/harems don't seem to be required