Were things really that bad before the Targaryens arrived?

[SeanF]

The only way that unification would be worse than what went before is if the Targaryens embarked upon a campaign of imperial conquest that failed, and left the country under foreign occupation, like Germany in 1945.

[Lord Varys]

Regarding councils - the pre-Conquest kings would have their own royal councils, but it would have been a different system.

What might be kind of new in the Targaryen Small Council is that no office there was (actually) hereditary and only two positions were mandatory (Grand Maester and Lord Commander of the Kingsguard), allowing the kings to appoint advisers whose counsel he actually trusted and who actually had the ability to fulfill the duties that came with the office.

Most medieval royal councils and the like included the highest ranking nobles of the land by default, meaning you did not only have folks on your council who might not exactly be able to offer you good advice, etc. but also who might view themselves as better kings or even be your (former) rivals for the throne, etc.

The Targaryen Small Council had none of that. It actually shows the power of the Targaryen monarchy that they could afford to exclude the great houses from the actual government of the Realm. Certain individuals were included now and again - but not the great lords

That some position and offices of high prestige and power were hereditary in the old kingdoms we see with the Tyrells being the hereditary stewards of Highgarden which apparently came with considerable power and influence at the Gardener court. Something similar may have been the case at the Lannister court in the West (where many branches of House Lannister may have held hereditary positions at the court of the King of the Rock).