I think Larry’s got the right solution, but it might be a lot better with a couple of mods…

For starters, I’d put the arranger on the top surface. Stable, no bounce, no risk of wobble or the shelf becoming looser over time (those shelves are usually only supported by wood screws into the underside of what is likely to be particle board wood). Put the computer keyboard, mouse and other things like the interface on the slide out tray. A LOT easier to get to while recording than having to reach over the top of your arranger while you play it!

Next, I’d extend the monitor shelf wider. To accurately monitor audio, you should be sitting at the apex of an equidistant triangle. From that photo, looks like those monitors are a bit close together. A lot of computer desks today haven’t kept up with the size increase of monitors, leaving very little room outside for speakers. Either a plank full width or a couple of shorter extensions either end would help…

If you think about it, what are you likely to be doing most..? Playing on the arranger, or editing music? Hopefully, it’s playing! Prioritize that in how you lay out the gear and it will be a comfortable music creation environment.

By the way, a good adjustable height chair that you can lock from rotating will help with posture when either playing (higher) or editing (lower), as it won’t be long term comfortable with just one height. And rolling office chairs that spin and slide are tough to play in!