Avery sent full power to the Dauntless' thrusters and aimed to close in on Atlas' vessel.
To pierce through his opponent's defenses, the best way was to get in close and fire his plasma launchers.
Even large vessels could not block the superheated plasma easily, so no matter how strong Stifur had made their craft's shielding and armor, it probably would not be able to take more than one hit. A second would pretty much guarantee that the ship would be destroyed.
Naturally, with his wealth of experience as a mercenary that went well beyond what Avery had; Atlas was well aware of this.
In terms of speed, his ship was never going to beat the Dauntless, but there were other ways to prevent an enemy from getting closer.
Obviously, the team at Stifur that had designed Atlas' vessel knew that attacks that could penetrate through defenses would be a major weakness. That was why the weapon systems that had been chosen were meant to compensate for this.