Maybe it's harder to deal with ten projectiles in a minute followed by a nine minute reload than one a minute for ten minutes?

Even a short surprise can be crucial in an ancient battle, where breaking formation can be fatal

I'm not even considering the magazine reload time, just the time between shots assuming a full mag. That's 10 recharges either way, as shown in the videos. It's not like a machine gun where the energy is in the powder.

Very likely.