Every cannon has a area attack, doesn't mean nothing.
yes, Yes, but if you have 5 units together and if a cannon attacks all 5 will be affected, but if you have 10 or 20 only 6-7 they will be damaged.
even with the weakness against skirmisher, a single doppelsoldner is still too strong. Remember it has 945 HP, I don't think a pair of skirmisher will kill it
But you are not going to create only 2 skirmishers, with 5 you can beat 2 doppelsodner, but of course, if you keep them in a single formation and do not move them you will destroy them.
Mortars are extremely slow, you can easily destroy them, and you said that 3 mortars can destroy a single outpost, not 1 mortar.
And the demi is not slow?, an advantage that mortars have is that they have a lot more range, that helps them take a more secure position, also the cavalry has to move more distance to attack them, which gives them some time to escape and That other units come to support them.
And it is true, 3 mortars can destroy an outpost, not 1, but 3 mortars cost almost the same population as a single demi
Using spies against a such strong artillery is ridicoulous, you'll have to spend a lot of resources for a spy which can be easily kill in one shot. I understand those troops have weakness, but those are really really irrelevant against those troops' strenght.
You do not need to use spies against cannons, any heavy cavalry already does a good job, but against everything else they are very useful.
I'd would be happy if someone tells me why a landknescht has 450 HP and a doppelsodner has double.
Because they cost double the population and double the resources