After posting pics of some skirmisher bases with 4 figures per base, it seemed obvious that the majority of comments were pointing towards bases of two figures. I'd been feeling the bases were too crowded with four per base, so a new size was decided on.
Next I had to pop the painted figures off the old base. I really couldn't face completely destroying the base on these but thought I could try and lift the textured sand off and use that on a smaller base. It was easier than I expected.
The sand and PVA held together perfectly and I only had to carefully snap the sand in half to get two sets of separate figures.
These even fitted perfectly onto the new size bases. I'll use PVA to re-glue the figures onto the new bases, and they'll need some new sand added to hide the damaged edges, but they should look as good as new.
So, next on the painting list will be a 12 figure Skirmisher unit.