I've seen that many newbies jump on the biggest alliance just because they're bigger, they usually don't intend to be a 'part' of that alliance; they want to be in it because its bigger. This way a snowball effect is created and more and more people join and soon you get a large MRA. If they were recruited thoughtlessly, there's a very large number of them not interested in playing and becoming better at he game; they're the 'fat' that need to be 'trimmed' off.
Now if an MRA succeeds in finding all the good players, trimming off the bad ones, has enough expertise and leadership in it to communicate with all of its players, and know which ones are going to stay and which are not, that brings them one step closer to succeeding.
They now have to look at where their players are positioned, and assign small groups within themselves to work as a team. This is where good experienced players come in. They will have to co-ordinate support and attacks to counter threats in their areas.
An MRA cannot function without many experienced members guiding the new ones. Also, those should have very good leadership qualities and have the ability to communicate well.
As for their survival in MRA hostile waters; Very slim. It would become a trend in those worlds to attack MRA members. And the newbies, new as they are, would be very agitated seeing the slew of attacks and panic- I should know; I panicked quite a bit when I saw my first incoming attack long ago. They would ask for support and because of the size of the MRA, those that receive the 'help needed' mail would be far away and not even know the other player- and so, may ignore the request; thinking that it was for someone else to do. This is why dividing the MRA into smaller units will help.
Overall, the success of MRAs depends on having:
1 A decent number of dedicated, expert players who can lead and communicate well.
2 been able to pick out the good players with potential.
3 been able to divide and survey their territory for threats and made plans and teams to counter them.
4 gotten enough good players along with the bad in the start (the luck factor- like mentioned above).
5 ...
...
Not being sabotaged.
