Warmogs now only grants health regen while out of combat, but grants 4% up from 1%

That way it can actually be powerful at doing something unique that other items don't do. This item would allow your front line to regenerate between battles without going back, so you can better defend or apply pressure against or with a sustained push.

You can use the health regeneration on your beefy front line to absorb damage while sieging towers with your back line, and even if they are really hurt afterwards they can regenerate large amounts of health via warmogs so you can keep pushing after one or two waves without needing to go back to base.

If 4% turns out to be overbearing it could be nerfed to grant 2.5%-4% depending on missing health.