First, no one said using it as a combat ship, it ss designed to survive. Second, you are wrong about them not affecting ballistics. They effect the damage output of those ballistics with very minimal power draw compared to laser and disruption weapons, between 20% and 60% damage reduction. With the 890 having 2 capital sized shields and the devs saying that will be above regular civilian class by default it is unlikely the HH can output enough damage by itself to cripple or disrupt the 890's ability to get away, which is the point of the ship. Not only that but the HH is by nature a fleet ship with limited solo patrolling ability, while the 890 is outfitted for significant distance. It can afford the run away, the HH cannot afford to chase it.Shields do not affect ballistics. They go right through to the hull, and if that hull is not military, you should expect it to cough and die in just an instant under the HH's guns. Hull and armor are the only defense against ballistics.
You can see this prejudice for military designs v civilian all across the game despite armor is not implemented yet. For instance, look here:
Web application for planning and comparing loadouts of Star Citizen ships with detailed component breakdown and summary statistics.hardpoint.io
Compare the Vanguard Hoplite, with hull 26,800 and shields 14,584 against the Cutty Black with hull 3,880 and shields 7,292. This is the kind of difference CIG intends for the game, and why I am always urging people to keep in mind the difference between civilian and military designs when it comes to combat. Yes, you can use a luxury yacht in combat, but no, it's generally a very bad idea against a military design.