I have taken over a country in a Frontier game in DAY 3.
The Country was played by the AI
It is a Clash of Nations 22 player basic set up.

For three days the A.I. has researched:
militia 1
infantry 1
mot. infantry.

NOTHING else.

The A.I. has
built in two cities level 2 naval base (but no ships because they have researched any)
built 1 airplane factory *suspected was a starting facility
built 3 sets of level 2 infrastructure on provinces that are core, two of which are mountains
built 2 other infrastructure level 1
built 2 level 1 factories in urban
built 2 level 1 local factories and started to raise them to level 2

BUILT NO TROOPS
Built NO barracks, ordinance, Tank or Special factories

This is a TERRIBLE performance for an A.I. and needs attention since I suspect it is reflective of not just the major powers that are not played from the start but also the A.I. that takes over when someone drops out.

also to add on to that, AI does not immediately start acting in the beginning of the game since players could still join in. Usually AI starts building stuff on day 3 or when attacked earlier.

This is simply wrong, and a design flaw that should be avoided.

So make it that the AI does not spend on useless things.