I'm a total Dynamis noob, still got no LS for it (CUE SUBLIMINAL "zOMG PRZ LET ME JOIN" SOUND), so bear with me here.
Can't you just /sea? That shows everyone in the current area, which during Dynamis would be... your entire group. Or does that not work in Dynamis zones? Or am I not understanding the cmd you're using? Or am I a purple donkey with a whacky waving flailing arm flailing inflatable tube man on my dong?