Seems the GM I am playing with may have done something that he may regret.

He is allowing us to take ANY signature ability for a F&D career, though just one, which is normal.

I play someone highly invested in Ataru Striker and has Saber Swarm and such.

If I were to take Unmatched Ferocity would I be able to do Saber Swarm a second time?

I know I'd have to take the lightsaber choice of course, but would it be possible?

Technically you can take both from a career. You just have to take a second spec from that same career.

Just s clarification on taw.

Saber Swarm + Hawkbat Swoop and 2+ Force Rating is the ultimate "screw you" to any NPC.

Once had a PC deal 72 damage (18+18+18+18) to the BBEG in one round because of that. 10 was soaked per hit since the BBEG had cortosis weave in his armor, but still, that's 32 damage coming through.