These kind of dominance displays are normal - it’s how boars reinforce their relationship…..Provided one is dominant and the other backs down.
If any face offs are becoming more frequent or acrimonious then that can mean a dysfunctional bond.
It is a myth that piggies would sleep on the same hide - most never do. The only time I’ve seen my eldest pair of boars in the same hide is if some startles then and they happen to both run into the same one!
So this on its own is not any sign towards a bond issue.
Most boar pairs if they’ve been together for a long time and get to this age still together, are usually absolutely fine. Occasionally they can get to the end of the teens and decide they don’t like each other but it doesn’t happen often.
The guides below explain a bit more about what is normal and what are warning signs in boar pairs. They also explain how to do a temporary separation to test a bond is working
Bonds In Trouble
Boars: Teenage, Bullying, Fighting, Fall-outs And What Next?