Lions have the size and strength advantage, but hyenas have the smarts. Research shows that spotted hyenas outperform chimps in collaborative problem solving tasks. They also ‘speak’ to each other in different ways. Their whooping noise, signals intent or need to other hyenas. Like: ‘hey, we need reinforcements against these lions.’
A simple mistake by the lion could also get it killed as a hyena is not a creature than can easily let go. The only chance that a hyena has of winning is if it is fighting with an old, sick or young lion. Sometimes several hyenas attack a solitary lion and therefore overpowering the lion. However, the speed with which an African lion moves makes it hard to catch it, let alone kill it.
Please watch: “top videos 2019 on male lions fight for territory,”