Training wise I can't see ever recommending an RB training on a guard
nothing bad about having IS ID or SB on ur guards i think they all help & like u say they r free
but ill tell u why i recommend RE training 4 guards
its all about the timing
end of season u have no competitive games
sure u could train stamina but u can do that any week
sure u can train js or 1on1 but u can do that any time mins screw up for normal training (last 2 weks in a row grrr)
but why not once a season do something difficult & train inside?
if u only have 2 trainees sure do IS ID or SB
but i always have 3 so want a 2 pos training...RE
also means i can put 1 big man in as well and maybe boost a sublevel somewhere
i have done it 1 time/season most seasons since ~ s12 & love it