So when Theory crafting for X-wing there is a very delicate decision to be made. Strength in your Pilots Skill (PS) or just pure numbers. It's rare you can find a balance of both mini swarms and an Ace is doable but takes considerable time to master. Big ships you say, another animal altogether.
So where do you go? Early on Aces are tempting bit more forgiving and generally can be stronger. Your not watching as much on the field, which helps and for those of us who fly for the Empire, it's easy to practice the art of Arc Dodging. The down side of this beautiful strategy, not very forgiving, errors can glare at you as you take your ace off the field because he's been shot down.
Swarms on the other hand are lots of fun, create organized chaos, and mistakes can be minimized through sheer numbers. Early it's tough you get shot at first usually, you will cause yourself to be blocked and not get where you want, let alone where your opponent wants. You can get in the same occasional lower Ace in the mid as support, just don't get discouraged when he's the first to go down. Plan for it actually and sometimes you catch your opponent unaware of the box he put himself into. Trading a small Ace in a swarm for a Big Ace in an Aces list can be satisfying.
Big ships, oh where to begin? Expensive, tough, brutal, and oftentimes its Feast or Famine. Big ships are targets, and even lower PS larger ships will cost you a good 1/3 of a list without upgrades. Aces can be 1/2 of a list or more once you load them out making it hard to get them help. They fly differently so if your going to fly then stick with it the first few times out you WILL hit debris.
Best advice see what your ships do, see what abilities you're comfortable with, and drill your squads (Practice). Learn the ships you fly and what makes them effective then pair them up accordingly.