(Spoilers All) Three heads has the dragon - A new angle?

This may have been discussed before, but I can't recall it so I think it may be a new twist on a previous theory.

The dragon has three heads. Dany hears this over and over, and we know the three headed dragon is the symbol of House Targaryen. In general, the number 3 is very important to them. Three headed dragon as the sigil. Three dragons used in the conquest of Westeros. 300ish years of Targaryen rule.

And then there's Dany: three dragon eggs turn into three dragons. Three fires, three betrayals, and three mounts she will know. And the dragon has three heads.

Dany is the only head about which we can be nearly 100% certain. Any three 'head of dragon' characters which does not include Dany would be tinfoily to a high level. The second head of the dragon that many/most agree on is Jon Snow. It's not 100%, but given that R+L=J is true, it seems very likely that Jon is one of those heads, especially given the other hints surrounding Jon and Azor Ahai/TPTWP. The third head remains more contentious.

There are several candidates for the third head, but before we address that, I want to move to another ASOIAF theme which may help us: Only death may pay for life. This wisdom has strong, strong ties to House Targaryen. We all know that Dany sacrificed Mirri Maz Durr in the flames and her dragons awoke, but she also endured the loss of the three most important people in her world before that.

Her only relative, Viserys. Her husband, Drogo. Her unborn son, Rhaego.

Those three died, and Dany now has dragons named Drogon, Rhaegal and Viserion. Only death can pay for life.

Dany's three dragons required death so they might live.

Why would the heads of the dragon be any different?

• Dany's mother died in childbirth.
• Jon's mother died in childbirth (Assuming R+L=J).

Tyrion Lannister's mother died in childbirth.

What say you, r/asoiaf?