I am using a Defeated player's lurkers and before I start excessive triggering:

Can defeated units be detected (move location)?

Can defeated units be given?

When defeated units die, does it add to their deaths?

And yes they must be defeated, because i want them to be visible without detection.

They can be detected. But I'm not sure which player they are. All players should always work nevertheless but maybe the dead player works too.

They should be able to be given.

Dead and Neutral players have no death counts.

Do you mean Defeated, or do you mean units for players that aren't there?

When a player runs a defeat trigger, leaves, or whatever, all their units are forked over to Player 12. Certain properties of such units (ex. color) are retained.