London broil shoulder cut

I’ve had it marinating for about eight hours. I’m a meat cutter, but im definitely still learning! I have never seen this cut before we usually don’t sell it but for some reason we had it today, I got it bc it was literally so cheap, it was 4.59 a lb or something like that

Will it be good to grill or on a cast iron for tacos? I’m looking for a more medium rare if possible with this cut I know to cut against the grain but has anybody ever made this before? And am I stupid for trying to make tacos with it lol?

My co worker grilled one last night he said it wasn’t as tough as he expected it to be