Using a door trimmer

[Tigercubrider]

i am doing some decorating and recently had my floors professionally sanded and refinished. The doorways have threshold strips - living room has double doors as a through lounge - due to house movement over the years the double doors in particular have a small amount of contact with the threshold and will rub or score it if not attended to.

I would rather not remove and rehang the doors, but would rather hire a door trimmer that slices the bottom off. I have seen one used a while ago.
When the door is open I have a clear 1-1/2" between the floor and door bottom.

It will cost £50 to hire the trimmer and I can do 5 doors easily in a day?

When the guy used a trimmer at work, it sat on the floor, using the floor as a track. Then the saw sliced off the door bottom (in their case because of carpet)

Just checking that my plan is ok?
Probably will lay down a sheet of mdf on the floor to protect it and allow the saw to slide along, taking maybe 1/4" off the doors.

Thanks