At this stage they should do 2 bastion units One with repair, stationary turret and artillery ultimate One with grenade, moving turret and tank ultimate
How is he overpowered? Bastion is a niche pick in most metas. Bastion is too clunky, his power revolves around one cool-down, his large hitbox makes him the largest non-tank character but he lacks the large health pool and mitigation to make up for it. Bastion is slow and sluggish and has limited mobility. If you say Bastion is overpowered, you have to be Gold or lower cause he is insanely easy to kill unless his entire team is working around him and giving him the resources he needs to be strong.