As far as I know, you can't.
There are some options to show the current application windows (control + down arrow) which displays the windows for the current application as equal sized (minimized windows get smaller thumbnails at the bottom of the screen)
but that isn't what you are asking for.
Submit feedback so possibly they give more display options for Mission Control in Mac OS X 10.11 may be the only way (and convince other people to do the same)