bandon while being a powerful sith, didnt stand out that much and was killed by revan who possesed about half the power of what he used to have. plo isnt that impressive either, but he was considered one of the best jeedai in the order and a respected master. i only really see bandon as powerful as maul, who IMO could easily be defeated by plo
If they don't use force, Plo Koon will win. If they do use force, it will be a long match yet Plo Koon will win. Bandon is one of the weakest Sith that i know about (and I know about alot of them) And Plo Koon could beat Mace Windu, but it would take about 2 hours because Mace would get tired. Mace could even beat Bandon.