Depends on if you have a male-female pair emerge in those three HRPs. If so, you may wind up with just the pair of HRPs in that four foot long aquarium (the non-paired male or female HRP is likely to be killed by the spawning pair). Unfortunately, a single Amatatlania cichlid type such as an individual A. myrnae, would probably be treated no differently by the spawning pair than the extra, non-paired HRP. The Tapajos geophagines would definitely be considered a threat and attacked constantly by the HRP pair, as those S/A eartheaters will roam and forage almost non-stop on the bottom of the tank.
And lastly, the S/A Bolivian Ram is just too peaceful and weak IMO to be kept successfully with just about any C/A Cichlid species but A. nanoluteus in the aquarium.