Army setup - any best practises?

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Late game techs reduce the frontline width.
This means:
(1) CAV becomes less useful as a combat unit (since it won't be able to flank).
(2) ART becomes more important, since only ART can fire from the second rank.
(3) Numerical superiority becomes less useful as time progresses.

A late game army without ART lacks firepower per frontage and will suffer heavy losses against an enemy that is fielding at leas 50% ART.
In fact, ART is so strong from tier IV onwards that you can rely on ART-only armies.

 

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I think with AHD guards are no longer cost efficienct enough to justifiy them as your main infantry unit.
You can add a few stacks with guards to your army, but INF (or pure ART) does the job just fine.

 

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At first I regarded guards as an elite bonus unit. But they cost only a slightly more than inf, I'm insanely rich and don't have much primary/accepted population (Netherlands), so why waste it on inf?

Why waste them on guards when you can have ART?