What is different in 1.3?

[FactionHeir]

Those stacks do nothing against a well planned blitz naval invasion that can take out a faction in 1 turn (2 max)

Example: Me Spain control most of Western Europe, allied with Brits. Brits declare war on me for no good reason and I just use the 3 sloops in France and Flanders to land my garrisons of France, Flanders and Netherlands in Ireland, Scotland and London and take the Brits out in the same turn.

Rather than giving the AI huge field armies and no reason to builds its economy and research properly, it should be able to just keep a good size garrison for their cities and not stack up its units in the middle of nowehere where they do no good to anyone.