Option to rearrange tools in Painting Mode was added to version 2.3. It will be released probably next week.
How about in normal mode? I feel like it is more necessary there than in painting mode because that’s where you mostly have the issue of many tools together. Honestly, this is one of the few things that are keeping me from switching over from the classic version.
Since long-pressing on a tool currently doesn't do anything, it would be pretty cool if you could drag-and-drop the tools wherever you want them to. Please consider this in future updates.