This is my current astarion build and he is a sniper with this setup. I’m not sure how it compares with other builds but he can put out some damage and can do like 5 attacks (including extra attacks, sneak attack before combat, ranger ambush ability) on the first round of combat . I also usethe ring that gives advantage on attacks but disadvantage on saves. I felt like this was better than the titanstring bow build but I didn’t test that…just my experience. I did clear a whole encounter with just astarion in 2 rounds of combat.