Total Commander

In the file compare tool, the left window displays the TC left panel file and the right windows displays the right file.
But when using compare tool from rewriting file dialog, the left window displays the destination file and the right one - the source (which may make confusions as for the ordinary compare tool).
Is it possible to fix compare tool file order to be always uniform? (left window = left TC panel file, right = right)

But when using compare tool from rewriting file dialog

If you referring to using Ctrl+F3 in the dialog that comes up when trying to copy or move a file that already exists in the target folder, then you are note quite right.

The left window displays the source file (even if it is in the right panel, copying from right to left) and the right window displays the target file.

Notice that there is an orange arrrow at the top indicating the copy direction. This arrow it not shown in ordinary file comparison.

If you get confused, just always copy from left to right, then the files are shown in the same order as in ordinary file comparison