[quote]As for the other ranks higher than knight, no need to add an extra shield. Just have the sword(s) positioned behind the shield and there's your rank. Personally, I think blades crossed downward would look better for the knight captain. For the knight commander, it ought to be basically a combination of the senior and captain rank insignias, so crossed swords with one in the centre. I'll also say that the job of the knights isn't to command, that'd be the general's job, though they can give orders to anyone of lower rank if they want. The most valuable asset about a knight is their fighting ability, so their only job is, well, to fight. As the most powerful ki users in the military, each knight is basically a one man army so they're only ever called upon to protect someone or something very important, or destroy a particularly dangerous individual or group. Think of them as special forces and artillery rolled up into one.[/quote][@TheMerlin]

No problem, I agree with you on how it looks, it is just the symbolism I looked up, with blades down means the fight is over...
(weirdly enough) And I was thinking more in terms of visibilty when in the heat of battle the blood and dirt cover the armour, you might want something else as an indicator. (Not to fight you on this, but to show you my reasoning for giving the suggestion to include it)

Whilst the Knights don't command perse there has always been this 'special treatment for them' through history most of the time because they were nobles, lesser lords to their own lord (the king). Very similar to 'the Bannermen' in GOT. 
They would usually command their own people, those that lived on their lands or lived nearby.