Do I just see 1 powerhead at one end and one at the other.. but offset. I’m assuming they’re not controllable. I have the same issue but I think I even have a little more rock than you; and I thought if I had more rock it would help make obstacles (and hopefully not funnel). They look pretty high up but I guess they’re still making a good gyre.
I have not tried this yet but I wonder if you point them at each other if this wouldn’t make too much of a dead spot in the low corners.
I place my corals that don’t want high flow on the opposite end of a powerhead on one side and that still seems too much. I have the ones that can handle more flow kind-of guarding the ones that don’t need or want it. Idk if it would look too dumb to add one rock to deflect flow a little in an area of interest.
I have the same problem but I was able to find a third powerhead and I was going to try to add this on one end above my rock work but turn them all down. Conversely, I’ve been toying with the idea of mounting on the back wall and have two circulating gyres; not sure if this would work with my filtration and if the flow would deflect off the front glass ideally. Not sure where your overflow is.
Hope we can get this figured out for you.