I have a 180g with 2 small V. Regani, a small unidentifiable Vieja (see my other thread if you want to try!), a 4" V. Argentea, and a 4" V. Synspilum. Does anyone think it would be a problem if I added a small sized Midas/RD and/or Green Terror? I haven't mixed these more aggressive types of cichlids before. Thanks in advance 