it really depends on the paper ..
i have taken many portraits with modeling lights and
flash. graded paper and VC paper are sensitive ( it seems )
to different types of light so do some tests before you shoot ...
( i have used a lot of agfa grade 1 ( and 0 ) paper
and it took 3 600WS bursts through soffboxes to get a good exposure
and without the flash same soffboxes, same modeling lights 30-40second exposures )