Do you mean Viking AND Roman movies, or Viking OR Roman movies? Because (historians correct me) the Romans AND the Vikings were centuries apart. On the other hand, the Germanic tribes DID kick Rome's efete seven-hilled arses, more than once. Those just weren't "vikings" per se, I think.
Now, do you mean "Gladiator" movies, Johnny? Have you ever seen a grown man NAKED, etc? (Y'know, the famous scene in AIRPLANE etc)
I dunno about 'genre' but I bet if you can write anything that makes the movie guys see another GLADIATOR ... ka-chiing! I'm thinking THE 13th WARRIOR (am I remembering the title right?) made worthy box office dollar$ too. The "sword&sandal" swashbucklers used to be huge in the 50's ... and if what goes around comes around, maybe those are due for a comeback? CONAN was big ...
I mean, who would've thought PIRATE movies would be huge again (at least that one Pirates of the C. franchise, but what was BIGGER?)
World don't need another cop movie, imo.
So I won't be the one to poo-poo your good thing! Write what inspires you
My suggestion would be: choose your TONE carefully. There's not a huge FAN BASE waiting for a Viking movie, maybe, but catch the right tone, make it "cool" to modern audiences and you're home.
Who wouldah thought GLADIATOR would work?
Or 300?
Be the 100th COP movie someone sees that week ... or the ONE Viking movie.
Viking stuff might lend itself more to FANTASY. No one will buy a Roman running into a dragon ... but a VIKING can stumble into any weirdness. Vikings are "other" ...