No ones talking about making Easy-8's heavy (E8), we're talking the much heavier Jumbo (E2) @ 42 tonnes

I think the weight/armor define how it should be classified, also taking into account scale gearing. Look below, I've prepped a list, it can clearly be seen the weight plays a part in where its classed. Look where the Jumbo fits in the overall scheme of things

15t M5 Stuart
18t M24 Chaffee

22t Panzer III
25t Panzer IV
26t T34/76
28t Cromwell MK VIII
30t Sherman
32t T34/85

41t Churchill Mk VIII
42t Sherman Jumbo
42t Pershing
43t KV1
45t Panther
46t JS2
57t Tiger
68t King Tiger



I would put it like this (taking other scale factors into account):
Light = sub-20t
Medium = 20-39.9t
Heavy = 40t +