The cymbals are a separate kit with a few different cymbal types put together and the marimbas need to be grand staff because of the range they play in.
I have also gone into the layout options to turn off the instrument change labels and they still appear.
Any thoughts?
What would you consider to be “correct”?
I disagree. This is the notation that Finale writers use.
would you like examples from Sibelius as well? I have examples going back to 2010 from multiple different organizations and highly influential Percussion writers including Ian Grom and Shane Gwaltney.
That is the standard notation.
If you just want someone to argue with do it somewhere else.
Welcome to the forum. Can you post a stripped-down file with the issue here?
I’m not looking to argue. I’m just suggesting that your precedent is set by limitations in other programs rather than notational logic.
Ah, I see. I would recommend using the custom instrument function to make a grand staff instrument. Then your instrument changes should be correct.
Trying to get you a file. But I will try a custom instrument, Thank you!
MarchingBandMallets - Full score - 01 1.mxl (6.1 KB)
Each player should have a mallet instrument and a cymbals, this file may have separated each cymbal into a different player.
I also tried a custom instrument but I cannot get one that will let me edit the percussion kit while also being a grand staff.
Yeah I can’t think of a “proper” way to do this. You’d have to fake it. It’s certainly possible.
You might consider using two different (fictitious) Players for each (what I imagine to be) percussionist, one holding the cymbals (and other unpitched percussion) and the other holding the marimba. Put both players into a single part layout, and through judicious use of system breaks at transition points, make them seem to be one Player.
I think I like the cues version more 
My solution is to just add the cymbals to the marimba part, change the note heads manually, turn off playback, and create a fake player with the actual cymbals so I can still hear it.
This would easily be fixed if I could add a “bass” clef to non-pitch percussion though.
