Hi KathS
Sounds like you had two males there – and you are most likely to see males this early in the year, as they tend to emerge from hibernation earlier than the females. Although some hogs seem to be choosing not to hibernate these days, so there may be some females around as a result of that.
It’s quite normal for males to ‘biff’ each other, sometimes one rolling the other up and pushing it along for several yards. If one of them doesn’t submit and roll up it can become quite aggressive. But sometimes they do ‘biff’ into the side which can appear as if one is trying to flip the other. It doesn’t seem to do them much harm and a previously rolled up hog will usually eventually unroll and continue where it left off (the spines have a bit of a cushioning effect). Although sometimes a dominant male will keep a watch to see if the other unrolls and give it another biff to roll it up again, until he gets bored and moves on!