In both SP and MP, I keep getting into these weird end-game battles, especially on medium sized maps.  The scenario is that you have a roundish map, one single enemy left, you own about half the map and the enemy owns half the map.

The possible conflict area is so large that you can't really bottleneck them, and everyone has so many resouces coming in that it almost doesn't even matter if you or they lose a planet or two. 

So the question is do you, at this point, stalk their superstack fleet and try to eliminate it entirely (which can be difficult to find and track down their big fleet) or do you split your fleet into multiple medium sized fleets and try to take 2=3 planets from them for every one that their super stack is taking from you? 

Stalking (watching and not intervening) and then Chasing down their fleet can be a good strategy because even with unlimited funds it can be difficult and time consuming for the enemy to coordinate a massive rebuild and you can mop up while they try to build back.

But it can be difficult to stalk a very large fleet that is constantly moving because either they kill your scouts or you commit too early to a battle. 

Also, at the end game do you have one or two planets with max frigate factories (no other tactical) or do you try to have multiple planets direct their production to a rally point? 

I'm having lots of trouble with these end-games.  The micromanagement seems overwhelming!

Both strategies have their plusses and minues.