[DirectorTsaarx]

You can edit strategies by selecting the Strategy window from Empire Status (I think). Once there, one of the options allows you to set which ships break formation. The default setting is to have ships "without weapons" break formation. Unfortunately, Point-Defense Cannon are NOT considered weapons, and therefore a ship loaded with PDC will always break formation. That may also explain why the ramming attack worked when the ship had no weapons; it broke formation from the fleet, and was free to pursue its own strategy. When a tractor beam was added, it was treated like other "armed" ships and was forced to follow the fleet strategy (which I assume was NOT kamikaze...).