Perhaps, but he'll be wanting the pole after a short while, especially if it's
windy

There's no requirement for a staff, just requirements for a staff if you choose
to use one. Early in my career, we went through the arguments here as to
whether you could/should use poles with a flagger paddle! Actually, we were
just changing over from flags so there was still resistance to the great
unknowns of stop paddles & even poles that flaggers could lean on and so
possibly not be as alert. The MUTCD doesn't yet require a pole - but you might
check with your state & local roads people to find out if there's a rule that
goes beyond the MUTCD.

Yes, it would be legal, but a seven foot pole is recommended. This will allow
the Stop/Slow paddle to be seen over most SUVs. The paddle will seem to get
heavier as you use it without the staff.

Are STOP/SLOW paddles required? Can flags still be used?

Flags are supposed to be used for emergency traffic control.

I guess the idea is every truck can carry a flag or two, but the paddles and
poles are a bit bulky. You are supposed to change to paddles as soon as you can
get them to the site.

The only other time flags would be preferred is at an intersection if you don't
have a separate flagger per approach.