Hoping this is helpful:
The first time I used a tugger was as a helper. I was alone at the time (the boss trusted my problem-solving skills early on) and had to pull a 400a 3ph feeder through an underground conduit to a new kitchen in the basement of a church.
(We also added a third parallel service entrance conduit and conductors, run through the same CT's. It was fun watching the POCO guys closing the primary cut-outs. They had to reset the last one several times, and the arcing was spectacular.)
The tugging pulled up on the bottom of the panel, so I shaped a 2x4 to fit between the head of the tugger and the edge of the conduit bushing so all of the force was applied between the tugger and the conduit, not between the tugger and the building.
My point is that it may not be necessary to attach the tugger to the floor if you apply the force directly between the two objects. I equate it to loosening a tight pipe joint by applying force to two wrenches rather than between one wrench and your feet.