I've recently been uploading some series of images, using the upload wizard. They are numbered sequentially (with gaps) by the camera, (e.g. DSC_0123) and I am careful to select them in the correct order - but the wizard still randomises the order, meaning that if I rename the first, with a name ending "01", and use the tool "Copy title (with automatic numbering)", they are no longer in the correct sequence.

Others have reported the same issue; see:

https://commons.wikimedia.org/w/index.php?title=Commons:Village_pump&oldid=169065278#Upload_wizard_image_sequence_annoyance