While real people are all the same scale, they do come in various sizes.
The deviation with 1:10 would be indistinguishable, but probably difficult to find. 1:12 figures should be easy, but would be of small stature which, if all the figures were the same scale might still look OK. 1:8 might be available, but would look big. Smaller figures should be lighter, and less likely to get in the way of operational bits.
Learning to sculpt figures would be quite an achievement, and from what I have seen, is a talent that you either have or don't - I fall into the latter.
Just thinking aloud.