The next year you should find your broadleaf weed populations down to the level where you can grow canola with no in-crop broadleaf control needed. Plan around your volunteers. They always seem to show up to help you when you need them the least. For example, barley in flax is easier to manage than barley in wheat. Weeds tend to like these areas.
Forages compete well with thistles, scentless chamomile, resistant wild oats, etc.
Keep in mind, forages seldom drown out, so they can provide you with multi-year weed control and still bring in a respectable income per acre. Keep up on the varieties you use. Fast starters will give you quick ground cover. A good competitive crop will cope with most weed problems. Try increasing your seeding rates to help get a more competitive crop started, especially in your oilseeds.