While the Texas, Green Terror and Jack Dempsey may be able to currently get along your 55
gal tank, the Blood Parrots will not be compatible
IMO under any circumstances. These three fish outmatch the BP's individually aggression wise, much less all together.
BP's are a peaceful/semi-aggressive community compatible fish who will be terrorized by these other fish.
Now as to your current fishes compatibility....
IMHO these fish will "NOT" continue to live harmoniously, especially in a 55
gal tank.
Texas Cichlid 12" aggressive, very intolerant of other fish, best kept in a species tank.
Green Terror 12" aggressive, but compatible with similar sized/dispositioned fish.
Jack Dempsey 9" aggressive/pugnacious, may be able to keep with larger aggressive fish (Green Terror likely tankmate).
The Green Terror and the Jack Dempsey togethre will need a minimum 75gal (MINIMUM!), preferably 100gal+.
I wouldn't "attempt" to keep these three together in any thing smaller than a 125-150
gal tank....
Heck! I would't attempt to keep these three fish together into maturity, period.
Just my $0.02