I'm a Soldier and have Grunt and Garrus alot of the time. Most people seem to prefer squad mates that complement the player, I just take a brute force mentality - Grunt is simply indestructible, has limited Biotics, and anti-organic ammo, and Garrus is his usual badass self with anti-anything abilities. Between the three of us, everything dies super fast, even the big Mechs.
As soon as I can via the research and Loyalty systems, I get a bonus ability for defense (either Barrier, Fortification or Geth Shield), that way I can take a ton of damage.
Played on Veteran the first time through, didn't find it difficult. ME2 on Veteran isn't easy, but it's not exactly hard. I think I died 3 times overall.











