I'm not quite sure what you're asking - if you mean, do I have to use 54mm models, then the answer is no. You can use whatever scale you want, 6mm, 28mm, 54mm, 75mm even play using life-size mannequins if you want. 1" = 1 yard is the scale for playing with 54mm miniatures, so you just need to adjust that if you want to play at a different scale.
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