Not all armies are in the battlefield . countries have reserves so they can launch a second wave.Why cant WL have it and reserves grow out of the income you receive but don't deploy. So the army is stored and kept in reserve for future use

I think this would be slightly more useful than airlifts for about one game.

how is this significantly different from not attacking with all your troops?

Reserves would fit just as much as multi-attack, generals, bomb cards, and all sorts of other random customizable settings.

Or if people prefer, instead of reserves, allow commanders to place land mines maybe?

Local deployments or Deployment Limits (https://www.warlight.net/Forum/82395-deployment-limits-easy-new-rule-implement) are a good way to create reserves and/or supply lines.

Or you can have a team game, with the groups "behind the front" supplying reserves either via forced march or via Airlift.

What Poireau said

Not all armies are in the battlefield . countries have reserves so they can launch a second wave.Why cant WL have it and reserves grow out of the income you receive but don't deploy. So the army is stored and kept in reserve for future use

Umm.. Reinforcement card earned through card pieces

Isn't this reinforcement cards? You can just hold them...

hmmm, maybe being able to bank troops wouldn't be such a bad idea for an extra feature. In some rare cases you can have so many income before finding your opponent that banking extras wouldn't be bad. But it's arguably not very strategic...