Firmly agree with Helm and Uptown. Welded-wing doesn't work in sim as it does in RL, probably due to limited visual perspective as much as anything else. The alternative, I call Loose-wing, does allow pilots to separate some, but it's not so much specific distance that defines Loose-wing as communication and management of the engagement.
Rule One, as my squadron practices Loose-wing, is CONTINUALLY communicate back and forth with your partner, in very brief calls (using some type of Brevity Code, if you know some). Each pilots gives a running report of his position, tactical situation, and his intentions, as well as his opponent's movements, and further, what he may see of his partner's engagement and opponent. Obviously, this requires tremendous SA skill, the briefest radio comments without repetition (it's your partner's responsibility to be paying attention), and supreme coordination between pilots.
Rule Two is always stay in proximity to your partner. This means when you have the option to do so, turn your fight back towards your partner. One of the best tactics is one I call "Trade-A-Kill", whereby at some point you get a passing shot at your partner's opponent, or visa versa. And the number of times I've setup a bandit on my six purposely to allow my partner to pick him has to be approaching 4 digits.

Rule Three is think ahead of the fight by winning the OODA Loop. This is too involved to explain here, but it really means practise your coordination and tactics with one wingman extensively, and your ACM decisions during combat will come quickly, easily and accurately, and faster than your opponents.
In yesturday's BoB, during our first escort sortie in 110c's, Bmathis and I held off 3-4 trailing spits from reaching our Reichmarshall's Ju-88's for over 3 sectors by simply coordinating our dives on the highest threat while the other covered against any mousetrap by the other spits. They never got near him.
On our second sortie, with the addition of Leitwolf, the three of us continually defended two sets of buffs from a squadron of Hurri's and one of Spits (plus a couple stragglers, I think) in repeated attacks. One buff pilot did lose drones, but all of us made it home.
Hunter tactics while using Loose-wing flying with a partner is, IMO, the most fun you can have in this game.