I worried about what glue to use to fix the tank riders on tanks but found that the best Superglues ae not very effective and ordinary plasic glue I use for the model tanks is absolutely great.
What about white glue? I didn't try it on those sets yet but that's what I usually use for such things. Regular glue is good but is not "reversible", white glue is less strong but you can take figures away if you have to for some reason.