oh cool am going to check out the one page rules. I have been playing some super rules-lite fantasy RPGs with my kids (age five and three) but I think they are actually probably going to be more excited about a small scale wargame and this might give me some inspiration. On that topic are there any other super simple / rules lite wargame rulesets you might recommend me?

It's important to keep in mind that the only difference between "a wargame" and "a role-playing game" is often the way the player approaches the experience. Most people think of a wargame as something they come to looking to understand and master the mechanics first and foremost, specifically running for "winning." A role-playing game is often considered something you approach by putting on the mindset of someone actually inside the modeled experience with the player activity specifically thought of as not necessarily making optimal choices but choices that "the character" would make given what the player knows about them.

(I know I'm using a lot of quotes in this particular response, but I need to separate out the terms of art from what I actually think.)

If you look at a lot of historical war gamers, however, you see that many, if not most, are approaching the activity at the table as a reason to inhabit the role of "the army" which is engaging in the battle. Not only will they make nonoptimal choices, they will take mechanical systems which explicitly weight outcomes and abilities based on the character of the organization. The only thing that separates it from traditional role-playing is the idea that you aren't playing a single character but instead playing a group of characters which are involved in an ongoing experience.

Which is a really long way to go around the pole to say that any lightweight fantasy wargame system you might pick up is going to be a role-playing experience playing with your children because they haven't yet learned they shouldn't be thinking of the things going on the table as "not a character." They will say things like "my guys run up and fire their bows" and "my guy runs up and hits him with his sword!" They are all "his guys," and all part of "his character" just as much as a more traditionally architected game wouldn't differentiate a character with multiple hit points that loses effectiveness as those hit points go away. Just as the single character with reducing hit points and abilities remains the same character, a group of figures which lose individuals and thus abilities along the way still remain "the same character."

So all that crazy meta-commentary out of the way, simple rule sets that would be excellent for young players include…

• War Stuff: As mentioned, a great OPR option. Not too complex but with enough meat to get your neo-Chainmail/not-D&D fantasy on with.
• Warrior Heroes: Legends or 2 Hour Dungeon Crawl: Pick depending on where you want your focus; out in the wider world or specifically going into holes and hauling out loot. If you can get your hands on the older edition of WH, Warrior Heroes: Armies and Adventures, I actually prefer it to the later WHL because it's more sandbox and includes a random dungeon generator system I really like a lot.
• Mobile Frame Zero: Rapid Attack: Okay, yes, I know, it's not fantasy, but getting to put together your own Lego mecha and blast pieces off each other and the terrain? The role-playing practically falls off the table and I'm pretty sure the mechanics are simple enough to grasp the coloured-die/ability match ups even for young kids. Hacking it to be fantasy instead of giant robots wouldn't be hard.