I have tried it in the past, and personally I won't do it again --- others have had success with it.
Tried a health Haddoni and a health LTA in the same tank (( 58 and was running carbon )). Neither one would still settled in. Once I moved the LTA to a different tank the Haddoni settled in and stayed put, and the LTA settled right into its new (( but existing )) tank.
Prior to that I had an LTA and BTA in that 58, while neither one moved, the both looked better after being separated. Same was true with Haddoni and BTA.
Keeping the same species in the same tank (( different color morphs )) won't present any issues (( assuming the tank is "right" for anemones to begin with. I currently have 2 Haddonis in one tank and 2 more in another. All are doing great.
In the past I did two LTA in the same tank, and several (( around 10 or so )) BTAs in the same (( different from the LTA tank )) without any issues.