It's a numbers game. It's true that having few members will be hard for a faction to win a war. You may try doing what Spartans did but guys this is Granado Espada not some Greek or Roman War.
There are ways to fight this weakness.
What are Catherine Summoners, Diegos, Angies, Jacks, Vikis, Barons, and Ambers/Valkyries are created for?
Catherine the Summoner, the One Army Lady
(*)dolls are great breakers, imagine each or most of the members in the faction having Caths summoning her army of dolls. That's wicked. ^_^
(*)dolls can attack disabled enemies, whether stunned, feared, burned, shocked, frozen, knocked down, there is no time-out with these dolls
(*)defensive system, dolls are not created just to attack. they are in another way act as defense to the team. dolls can absorb damages from AOE attacks (although they die easily) giving the team higher chance of survival.
(*)counter-attack team. dolls are hard hitters we all know that. and they can counter enemy spells. the more the dolls the less chance for enemies to cast their skills
It's very advisable to have at least one Catherine Summoner in each family. Imagine at least 30 caths summoning 9 dolls each. That's 270 dolls guys plus the 30 Caths equals 300. Its like having 3 factions with complete members each. Spartans? Scary.
Diego/Angie/Jack, the con..err..destruction team
(*)Diego and Angies's blades are, of course, the best colony breakers as discovered by Mistress Hrin. The giant blenders as what they are now called.
(*)But their stance are named Defensive Construction, why, because these blades are really meant for defense. I know most of us experienced the faction quest inside Prison de Joaquin, you noticed the blades right? They hurt bad and they can knock you down if they catch you. These blades are used to prevent melee attackers from getting in. And for the range attackers, that's when Musketeers, Bernelli, Brunie and other shooters gets into the scene. That is also why in this stance you got the Concentration Ward to help increase the damage and accuracy of these shooters while taking refuge inside the blades for possible melee attacks.
(*)Jacks cannons are not as good as blades in breaking a colony because they are slow but are good for killing approaching enemies. And of course his Wards are really helpful in increasing your survival by staying within their range.
(*)And like dolls, their constructions can also serve as defense by taking damages from enemies. They of course got fences that are really meant to take damages.
Viki, the Boss Summoner a.k.a. Lagger Creator
(*)his summons also add numbers to team, serving as damage dealers and tankers. Because of their high HP they can survive longer than our normal characters or Cath's dolls or Diego/Angie/Jack's constructions. They are also great disablers because of their AOE attacks.
(*)and why keep on complaining about lag if you can use it against your enemies. Yeah Viki's summons are the most annoying of all because it blocks everyones view and also creates great lag to the game. -evil-
(*)Viki can be a substitute to scout. Although he is weaker, why keep one scout if you can have Viki and his summon. It's a Numbers Game, right?
The Barons, Kurt and Eduardo, help! reap! reap! help!
(*)they are just like Viki, their Reapers are good damage dealers and tankers because of their high HP, also with their rapier/saber skills they are also fast attackers (very useful in breaking), they are soft though.
Ambers/Valkyries, summons galore
(*)It must be compulsory that each faction member summons a Valkyrie or an Amber during CW's. These can also add numbers to team, and you guys now already know how beneficial it is.
(*)Low-level Valkyries would be enough if there's not much vis available.
Valkyries are really good breakers.
(*)Ambers specially those of Golden Spiders, Sabel Tiger, Giant Comodo, Fallen Champion, etc. are really must-haves. If you don't have summoners in the team, just summon these bosses to add number and see them kill and tank for you.
Now, you think a faction of at least 20 members will not be able to conquer a colony with these? ^_^