The figures look really small compared to that tank.
I really think that "scale" is an approximation, an expression to base a model loosley on.
This Higgins boat, which has since been purchased, looked much more in proportion than your FM tank. Again, it's an approximation.
Is K&C really 1/30th? Maybe, sometimes but other times it can approach 1/28th.
I really believe that scale is somewhat relative. Kind of like Forces of Valor. THey are 1/32nd??? Not exactly - more like 1/35th. 1/35th is in the range of 1/32nd just as 1/28th, 1/25th and 1/22.5 are in the general range of 1/24th.
Cheers,