This is true but in a game not played for score you generally want techrate on normal or even less and this will seriously hamper your ability to swindle the AIs because, they will have established a military long before you can do that (you will also go broke before having the SCC, psionic beams etc)
Further, the game is still full of bugs and if you use them all to your advantage there's no way you will ever loose a game on any imaginable setting. I speak of that because the swindle tactic is also nothing but a bug, or, an exploit of a really careless coded routine.
I understand that a civ will be very impressed once the enemys MMR far outweighs their own, but then, there's simply no realistic approach or logic in making peace (= which is a means of *survival*) by handing them over all your planets (=which is the exakt opposite of survival)
That said in a warfighting game the No Mercy Invasion Center can really be helpfull if paired with a special invasion technique:
1. The turn you invade put spies on all morale building on these planets
2. Use "Information Warfare" (costs 800 bc, said Center will drop it to 0)
3. Invade with maximum fleet, the more the better around 8000 soldiers will always do the trick.
4. Usually someting like 1000-1500 enemy soldiers join your forces
If you have enough soldiering the battle will be won without loss, in fact, it might be that you'll just loose 500 soldiers, and only one invasion ship. That way it can even be productive to use all logistics available to you and put a simply small troop transport therein too, because it could be the one that will be lost, saving the more expensive ships.
A second tactic which is also very effective (in cases where you don't have the upper hand so to speak) is to bomb enemy planets with a smaller force using mass driver or planetary bombardment (or whatever it is called). This usually results in reducing the planets popultion by a great amount. Be carefull that you loose that fight though, because then the planetary penalty will not be in place. Afterwards invade with normal troops.