Guess what? Mike Gamble is full of shit.
You're confusing the entire War Assets system. I don't blame you cause it's poorly explained.
You have your total military strength. That is the bar you're filling up with War Assets (that don't do anything in the game).
Then you have your Galactic Readiness multiplier percentage.
That only increases by playing multiplayer or using the iOS app and game.
Finally you have your effective military strength, which is your total military strength multiplied with your galactic readiness. A person playing single player only will always have galactic readiness at 50%.
So say you had about 7000 Total military strength. When you multiply that with your 50% Galactic Readiness, you get 3500 Effective military strength.
The "best" ending is only possible to get with 4000 and above.
Guess what? It's impossible to get enough War Assets in the game to go above that number by playing single player. There aren't enough war assets in the game. There aren't enough war assets even for an imported character.
Don't believe me?
http://social.bioware.com/forum/1/topic/347/index/10119654/1