They love to swim and really patrol a territory. A 75G plus sized tank is ideal because of their natural tendencies to control an area. Definitely they can be jerks especially when they are in their youth and probably getting the hormonal urges to breed and secure thier own space. I made sure there were what I called race tracks at the very bottom and around the 1/4ish to 1/3rd space int he tank. Kind of like figure 8 type spaces around the glass area at the bottom and room to pass Cories.
My Kuhlis never were in the direct area of the RTS. I guess they hid a lot.
The higher race track was more or less between Amazon Sword, Anubias and Eel grass, stones were more around the bottom, and big tall DW. There was a purposeful space for the swimming. and an open area for the Neons and Harlequins.
All fish would see the shark coming and just switch directions. He was a bit older, adopted him from a long time hobbyist moving and editing fish tanks from his new life.
They also like the stone areh or DW arch type caves to sit under, able to whip around and go out front or back, at any second!