When adding a snare drum and a bass drum, Dorico places the bass drum above the snare drum.
Placing the snare drum over the bass drum is better for me. (Am I the only one who feels inconvenienced by this?) So, I put the snare drum over the bass drum.
However, importing a musicXML resets the order. As a result, the complete order of the instruments is changed, also the bass drum stands again over the snare drum. Is it intended? This occurs repeatedly.
In the Players panel, you will see the Sort button, which has a little triangle in the corner to show that it will reveal a menu if you long-click or right-click on it. Choose None from the menu that appears to avoid Dorico from automatically re-sorting players when you add new ones.
It could be a useful feature to automatically switch to None as soon as there are any manual overrides. (Or maybe a Preferences setting to select whether this should be done or not.) If a user is manually rearranging things, it seems logical that they won’t want those manual edits undone by the addition of more instruments.