Will they do that much fighting even if they are configured differently? I don't think cperl-mode changes indentation just by typing and certainly not anything further than the current line... at least I don't see anything in my cperl config that disables any such things. cperl is happy to allow me to edit a line or comment that it thinks in not properly aligned without changing the alignment. (that's actually a thing that drives me crazy in some other modes - they change the alignment when I type a paren or semi-colon.)