Between the figures inside buildings and on the street I have almost 2,000 figures on my trolley layout. All are made from resin cast body parts. For the interior ones I use AC to hold the permentally in place. For the street figures I drill a #60 hole in one leg and insert a small brass rod that sticks out about 1/2 inch. Where ever I want to place a figure I drill a #60 hole in the sidewalk or street etc and plug the figure in.
Over the years I find this method most helpfull on those occasions when I want to reposition or replace a figure or need to remove figures so I can perform some necessary maintainance and do not want the figures damaged. Also if I do not want the figure replaced the hole is not noticeable.
Les Lewis