"Suffered" damage is damage after damage reduction, yes. But when text says "suffer" - it is before reduction effects (like it says on any attack action "Target suffers 1/2/3 damage", for example). You can't decide to "suffer" more damage than written on the card, if it says "Suffer 2 damage" then it is maximum 2 damage before reduction. By your logic I can choose my 1/2/3 attack to be 3/4/5 because I know how much reduction target has (it's an abstract example where 1/2/3 attacks hit model with armor +2 for example)