The ShieldSim will behave according to its difficulty level, with one caveat - if its shield is damaged, it will, whenever feasible, immediately retreat to find another shield.
ShieldSims are a waste of time. If there are shields in your game mode, just shooting out its shield will fend it away. Killing it instead will make it respawn with a full shield, repelling it for a smaller time.
Camping near a shield spawn will not only draw them to you, but you will have a full shield, and they have no where to retreat to, giving you hordes of points.