You don't need to disarm them all, just two, and you can do that by spamming the rockeyes just as a support ship docks with you (which you called prior to their arrival because you know both their spawn point and the time it takes for them to arrive), you also can at this point order the AI to attack a singular fighter if you're lazy or micro them out onto multiple opponents whilst you continue to take out a second and potentially a 3rd beam before you have to move (depending on how truly fast and organised you are), that means you've taken out the nearside fenris beam, and the two nearside leviathan beams.
Problem solved.
The /other/ trick is to gib the lokis with your wing mates faster than the beams can kill you all (whilst still having nailed the fenris beam I find this way easiest)