Yeah plus you'll want it to be nearest playerunit that isn't already being overlapped right?
It would normally be - for each enemy sprite > find path to nearest player unit - but since you want it to do checks for if the player has been targeted...
In its basic form, when an enemy unit overlaps a player, or 'has reached destination' in the pathfinding you could toggle a player instance boolean 'isTargeted'.
Then when you run -for each enemy sprite > find path to nearest player unit - add a condition under for each enemy sprite that player is not targeted (isTargeted set false).
Of course this is getting out of simple mode now as you will have enemies moving to a player as its destination before it is set to isTargeted so you will need to be either running this check every so often to find a new destination or use the 'destination failed' event on pathfinding.
If you want a specific number of enemies to reach that destination instead of just one, you could have the isTargeted as a number and add 1 every time an enemy gets there and when it hits 6 or whatever the total is then it doesnt become a destination anymore. You'll just have to build it a bit at a time to get what you eventually want.