You clearly never played MMO's before, as you would have known that Bosses are not regular mobs, they have Extanded attack ranges and larger hitboxes. As for your personal taste of how it should be done, make your own MMO and design them how you like. This is a standard Boss mechanics in MMO's. It's a downscale - or bosses for dummies, so they don't need to learn the mechanics of each Boss attack, and just look at the ground and dodge telegraphs. Back in the days, we never had Telegraphs in MMO's, but it was too hard for some players to learn Boss mechanics, so they began to add telegraphs, and now Telegraphs are everywhere, they even added them to BDO. As for desync between attacks, after years, you should have noticed by now, all NPC have it. If you run in different direction, you will notice the NPC's have a delayed reaction in to locating your position, it was made deliberately to battle server lag, since it's an Open World game, not instanced.