Good luck with your new pigs and you'll have a lot of fun for sure!
I started with 4 Bulgarian Whites last year. After electric fence training I strip grazed them in their field (20m x 25m) in 3 areas starting in mid-November. The field was very densely overgrown with all sorts of weeds, thistles, docks, jerusalem fartichokes, self seeded maize, etc. - generally it was 1.5-1.8m tall. And my intentions were absolutely to clear everything. They did a great job and the field is now resting (it's a bit claggy after the snow so a bit too heavy to tidy up by hand) before planting this spring.
I've moved them into a bigger paddock now (28m x 70m) and I'm grazing them in 5m strips. The field was deep ploughed 2 years ago but had been fallow for 10 years before that so it too has a heavy weed seed base that is just starting to sprout through the thick layer of brush cuttings that had been on the land for 6 months or so. I plan on seeing how long it takes for them to clear (properly clear) the strip and then move them to the next strip, and then just broadcast sow a forage mixture (rape, kale, radish) into the strip they have just left. With that paddock, as well as few areas in our orchard, outside our front wall (we have about 3m of weed covered earth between our boundary wall and road) I think I have about 16 available "strips" I can rotate them through before putting them back into the first strip again which, hopefully, will have a good forage crop for them to scoff down on. I am only feeding them one meal a day now as well as hand feeding fruit/veg treats to keep them handler friendly.
This is them in their original paddock in the snow, chowing down on a bale of Lucerne which they love.