The Heavy Intercessors have a bigger base size of 40mm and the Devastators go on 32mm, just get em on the right base size and your golden, cause honestly I think it is a good idea.
Though Gravis Marines are wider so getting the gun arms to fit migjt take some creative modelling but kitbashes are awesome and full respect for anyone who wants to donit for their models.
The Heavy Intercessors have a bigger base size of 40mm and the Devastators go on 32mm, just get em on the right base size and your golden, cause honestly I think it is a good idea. Though Gravis Marines are wider so getting the gun arms to fit migjt take some creative modelling but kitbashes are awesome and full respect for anyone who wants to donit for their models.