[Boron]

F E3 R1 is imo a bit too much .
F E2 R1 will do .

Because in battle all smith can easily cast summon earthpower and cast magma eruption/blade wind then even in unmodded ulm .
Since you build a lot of Smiths you soon will get as random earth . Then you have an E4 smith and with only boots of earth he can summon earth kings or cast the forge of ancients .

This elminates the need to put earth 4 on your pretender if you intend to cast forge .

So imo from a balance point F E2 R1 is enough .