Well, take this into consideration. I played the game for the first time about a year ago. Got a little over half of the achievements at that time, but had to cancel my gamefly subscription a little bit ago to save some money.
Got the game back a couple weeks ago, played it a couple more hours and unlocked the rest of them. Doing the missions on veteran gave me the biggest trouble. If you find a boosting partner for the rest of them, you should be fine, no problems.