Elite battalions and strategic uses

I've been mimicking Napoleon in my campaign in one major way - the use of an elite reserve guard, mostly made 'up of veteran companions and family members and as a grandfather now of some 30 children, I've spent a lot of money and time equipping them with elite gear and character plans to maximize effect. This unit of about 60-70 members I keep in reserve and apply on flanks or in specific moments to break the enemy line, turn battles or cause major damage before pulling back.

It's been very successful to this point though I do use a mod that increases the death chances for all heros and I've lost a dozen family members over the 20 years I've been using the mode(more death).

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Do you keep a reserve or elite unit, and if so, I'm curious if you apply it differently or in better ways.