Problems and solutions regarding Targaryen inheritance customs and polygamy

[Acatane]

Based on the main books of asoiaf and Daenerys dreams we we´re made to believe, that not only male, but also female polygamy would be an acceptable thing to do for a Targaryen according to their original valyrian customs. Maester Aemons words strenghten the impression, that Valyrians (like the Rhonyar) had originally a more progressive stance towards their females than Andals and didn´t know strictly male primogeniture. This idea is pointed up, by an unsual number of Targaryen women characterized as modern (or defiant in their own time).

I´ve always felt, that this liberal approach was retconned a little bit in the World of Ice and Fire. For obvious reasons. If Rhaenys was the rightful holder of the throne, why talk about Kings Landing all the time? We don´t learn anything about taking multiple husbands either there, only about taking multiple wifes. But in "real life" this approach would cause problems every time, when a younger sister had a son and an the older one with the claim had none. 

So, the most reasonable thing to do in this case (besides, that the marriage pool was bigger in Valyria) would have been to marry the oldest daughter to her uncle or nephew (and her oldest brother). My theory is, that this approach (the Targaryens shied away from, because they didn´t want to upset the local faith) would have prevented every major catastrophy for the House Targaryen. It would have kept the gene pool as big as it possibly could get and pacified the competitors from sibling branches like Maegor and Daemon also preventing the Blackfyre Rebellion. 

It´s even true for "our" Daenerys Targaryen herself, as we have many reasons to believe, that Jon Snow is her nephew (the third dragon head still missing*). 

 

*Yes, I know, that GRRM denied, that the heads have to be Targaryen, but he was forced to do so for spoiler reasons alone.
As the Targaryen women kicked out from the inheritance line against their will by the council, were great at coming back, I would assume that the third head is the Blackfyre  - Aegon.
And yes, it could be be Tyrion too, but this would be awful. 

 

I apologize for my bad English and plea for mercy, if the topic I have chosen for this post was not the ideal one. 

[Darth Sidious]

The Targaryens gave up many customs when they accepted the throne. One cannot be married to two. The resulting children from outside the marriage are born bastards. 

[Reekazoid]

Point of order: female polygamy would be polyandry. 

[James West]

If bastards, and specifically the legitimization of bastards can cause problems, just think about the disaster if polygamy is allowed in a system of inherited rule.  Aegon IV made his bastards legit and look at the problems it caused ever since.  Polygamy would have torn the kingdom apart. 

Daenerys will have three husbands.  It will work in her case because she will be the ruler of many kingdoms.  Each children from the husbands will have their own kingdom.  She will have rule over the Ghiscari, Dothraki, and Westerosi.  Three husbands, and potentially three children.  Such was not the case with her ancestors who only had Westeros.