Selling before buying gives you a known number to work with. You are not guessing at what your Warman home will bring when you make an offer elsewhere, and you avoid carrying two mortgages, though you may need short-term housing if the next purchase is not ready.
Buying first works better if the smaller home you want is scarce and you cannot risk losing it, but a lender will want to see that you can carry both properties for a stretch, and a real estate lawyer's fee, typically $800 to $1,500, is part of budgeting for two closings instead of one.
Whichever order you choose, the Warman and Saskatoon markets should be priced separately rather than treated as one, since Saskatchewan REALTORS Association figures reported for Saskatoon do not describe Warman's own conditions. Get your hand-reviewed valuation from Joel Dyck.