Clash-of-clans – Do heroes themselves count as a percentage of the base you are attacking

tl:dr Yes it is possible, but they have different town hall level requirements and costs, so you have to have a high level village with substantial resources to purchase both.

Barbarian King - Available at Town Hall level 7, and costs 10k Dark Elixir. This means you can potentially purchase him without spending money if you build and completely fill the Dark Elixir Storage which is also first available to you at TH level 7. Note that you can do this by spending gems, or by raiding - but you don't get a Dark Elixir "mine" till TH level 8. (It's painfully slow, so don't hold your breath waiting for it).

Archer Queen - Available at Town Hall level 9, and costs 40k Dark Elixir. This is substantially more than what your early Dark Elixir Storage can hold, so effectively you'll have a hard time getting her early on without spending gems. If you are very patient, or a very successful end game raider, then you may eventually get her without spending money.

Treat balloons like any melee troops with a splash attack, except they fly. So, lure them into a corner and then hit them with spread out archers, minions, or wizards (most common units that can hit air).

• Archers are cheap but will take them down slowly, which gives them a chance to fly over a group and take them out on death.
• Minions I believe will not die from the bombs dropped upon death, so you can take out an entire castle full of balloons with a couple if you can spare the time.
• Wizards will take them all down at once if they're clumped together and minimize how much damage they do on death.