I like the sound of the conversion kits, though as all my SCW stuff is 20mm it's academic only.
With reference to "line commanders" is this meant to be a specifically SCW thing? If so I can't see any particular justification for it. Or is it something which will be introduced elsewhere as well, e.g CWC?
There is no reason why you couldn't use Line Commander in other lists in BKCIV.
It was designed to facilitate the use of large infantry formations - and to keep the game flowing. I had originally conceived it as part of a prototype Great War Commander set of rules (still a very long way off being ready) but saw similarities in certain later wars - such as Russian Civil War, Winter War (for the Soviets); early PLA Cold War armies (as in Korea) or Iranian Islamic forces in the Iran-Iraq war, but in our play-tests it also worked equally well for large armoured formations.
It could easily be transferred to CWC (or BKCIV) more generally.
It is not a super mechanism - it has its disadvantages - but my hope was it might speed up play in bigger games - but also give a level of realism around junior commanders leading formations into combat.
I hope that helps?
Mark