Hi ThomO,
welcome aboard!
There are some thread over the net talking about "SOLO PLAY" Ruels.
I'll try to sum them up here to openly discuss and maybe improve them.
1) Use your own hand of card and give the "other player" just 1 card (draw and play it immediately, applying the relative effect).
2) Give each side their "normal" hand. Take a hand and do the "best you can" with what they have, then draw that side's new card but don't look at it. Then pick up the other side's cards and make the best play you can with them, draw their next card and don't look at it. When picking up again Side 1, they have one "new" card and you can just do the best you can with them.
Using this variant it's suggested taking out the "first strike" card, that lets the defender interrupt play and say, "No, I'm going to roll against you first." This one is just too hard (for me anyway) to deal with solo.
Also "Counterattack" could be a problem for solo, consider also removing it if this harden your solo play.
(this one is from Kevin Duke).
3) Whitout considering initial card hands, draw 2 cards at the begining of each turn and select the best of your choice and discard the other. That way you will never know cards in other hand, and it could be easier for solo play.
(this one is from Paul Dickey).
4) Roll a normal die for each side before their turn. If you roll equal or lower than the army´s command, take two cards. Select one and discard the other. If you roll higher you take one card and use it. Armies with command 6 take 2 cards every turn (as long as command does not change during the battle).
It´s a good way to play both sides without preference. It also keeps a little bit of the advantage of the army with more command. Very useful when playing historical scenarios. The bad part is it takes away the slight "strategic" part of the game you enjoy when having the full hand of cards. It´s more of a "how to maximize the turn" thing. It´s good training though and you never know what will happen next.
(this one is from Guido Quaranta).
5) use normal card hands for each side and rankd the choice of tactical cards before throwing 2d6. After rolling you will compare dice desult with a table like this: 6-8 is the best choice (ranked at 1st place before), 9-10 is the 2nd ranked card , 4-5 is the 3rd ranked, etc.
This method involvs some tactics and also luck.