Hmmmm, just sharing my experience as an experienced FB games player.
First to list my credentials as the fb player for the record:
Farmville (lvl 70 maxed)
Mafia Wars (lvl 720+++)
Castle Age (lvl 261)
Happy Farm 1 (lvl 40+++++)
Happy Farm 2 (lvl 45 maxed)
Space wars (game removed lvl 300+++)
Robin Hood (game removed lvl 200+++)
Dungeons and Dragons - tiny adventures (17th generation)
Battlestations (lvl 101)
Many many more
Now, u know i am not just jibberishing, here's are some of my tots of 'allies' / 'size of "frds" '...
1) On most of these games, adding "friends" (more like total strangers) became a norm.
2) Most of these 'friends' are of no use except for bullying others, often a very bad way of getting lousy reputation.
3) At maxed 'friends' like mafia or castle age of "501" (maybe zynga like 501), they give 'huge gangs' a chance at bullying another huge gang.....
4) There is no rpg elements in a sense (cos its all boiling down to bully tactics)....
Since this is aiming to be a unique game, i say, we consider adopting a style similar to battlestations in terms of friends / 'strangers'.
1) You may still attempt to invite frds on. (Frds tat is encouraged).
2) The new 'crew' does nothing to impact the game, hence discouraging mass adding of strangers, which BTW, is an infringement of facebook policy. See their revised policy.
3) If we want to encourage more folks to join, perhaps onli after they reached certain level (in this game, 20 or 30 is good), then u get credited an X nos of perhaps research + credits + Energy. In battlestation, we get credited 50 AP (Action points, or the energy equivalent).
4) Perhaps the crediting can be directed at a 'spare reserve' such as obtaining a certain 'tank', hence wont be wasted / overflow - which is fair, since its earned.
5) This encourages players (mentors) to help their new friends (whom they will communicate with in real life) to lvl up and helps em experience the true nature and beauty of this game.
6) We can also consider a guild, rather than legion. This way, guild mates will not attack each other. Much like real RPG elements of legions.
7) We can list the clan strength in ship profiles, hence discouraging nonsense, deterring noobs.
Well, my 5 cents worth.
Btw, IMO, BS is a HUGE success if you do not already know, and they have been voted best fb games, EVEN after switching the mode of play from adding players (they even used to have a requirement for X nos of new frds or crews, before able to unlock missions), to the current above proposed policy!
And also, if u really want more RPG elements, you can have 'wingman' of max up to 4 or 5, this way, your closest frds can become your wingman. Perhaps and only perhaps this way and these wingmans, can give u additional boost. You get hence, onli a max of say, "X5" (5 times) the bonus, instead of a mad 501x vs 5x......
This way, it makes a more fair game.
Btw, if u play space empires series, its almost #&$# to have 501 ships legion attacking the same place....../ ship..... pure far-fetching theory. AND yes, i am a very HUGE fan of space sim, space 4x, and space strategy games -> Ranging from the good ol' X Wings (series i love best, and title i love best would be the Tie Fighter vs Tie Fighter where u get to play bad guy! WHEEEEEEEE), to the Top Gun, to F15, F16, F18, F19, F22 series!

Consider this, Seriously.

PS: In fact, i find tat when u do intro a frd onto the game, they get lvled up fast and get 'hooked' LOL. Then they bring on more frds! I already have a couple of such frds, even when my legion is but 20 odd.

Think of it this way, would u wanna have 20 STRONG dragons allies, or 501 stupid flies?