If you are fighting a skeleton and it gets close enough to you, it will start to strafe to avoid you, the problem is, they move at around 7-8 blocks a second when they strafe and do not lose any speed while drawing bow. This makes them able to fight you like a melee mob with very far range and a high speed value. They acquire even more speed when going up or down blocks and can reach around 11-12 blocks/second on rough terrain. This may make sense for pillagers, but skeletons, who have no "base" should not be the fastest mob in the game (apart from endermen). Skeletons should either be nurfed if this is intended, or pillagers and skeletons swap places where the pillager outpost becomes the skeleton outpost