Referencing
Maro's article on Green:
Green's greatest strength is its absolute, unwavering belief in the natural system. Green embraces nature and is able to connect with it through that bond and use it in ways that are primal and very powerful. This connection also allows green access to many giant creatures that serve as muscle to help green push forward its agenda.
Green's weakness is its over-reliance on this system. For example, green is so focused on using creatures that there are a number of problems green simply can't deal with when it doesn't have creatures. In short, green puts too many eggs in one basket—and when that basket doesn't have the answer, green is often at loss for solving its problems.
In other words, green's strength is it has good creatures, and its weakness is that it has to play lots of those creatures. That doesn't really sound like a weakness.
I'll contrast with
white's strengths and weaknesses:
White's greatest strength is its organization. White is detail oriented and always has an answer to every problem. White has built up a complex infrastructure and is very efficient at using that infrastructure, be it laws, politics, or religion to its benefit. White's division of power, spreading evenly among all its supporters, makes defeating it difficult because no one piece is, unto itself, more important than any other piece. Finally, white has learned how to make small pieces interact in a way where their power is far stronger than the sum of their parts.
White's greatest weakness comes from its reliance on structure. White has no flexibility. It can only adapt to the things it predicted, and has great trouble when something new comes along. This inflexibility makes white slow to adapt so white can often fall behind when an environment changes. White also, at times, has trouble distinguishing how important any one facet is, as it likes to treat everything equally.
Another way to think of it is: white's greatest strength is its effective use of the group, white's greatest weakness is its disregard for the power of the individual.
In other words, white's strength is it can answer anything, and when it gets everything together, it's really hard to stop. White's weakness is that it can't respond to unexpected problems, and its cards are weak individually.
The 'strong in numbers / weak alone' element does come through in some ways - white has anthems to buff lots of creatures, and tax / prison pieces like
Thalia, Guardian of Thraben and
Ghostly Prison are very suffocating in multiples, but do little individually. On the flip side, the 'can answer any problem / can't deal with unexpected problems' dichotomy doesn't really make sense. The actual dichotomy in practice is 'white can deal with any problem, but it can't deal with
every problem' - white has both the most flexible answers (ex:
Oblivion Ring) and the widest selection of hate cards, but it runs out of those answers quickly. I don't believe that this is supposed to be white's weakness - if anything, I'd actually argue that running out of resources is supposed to be
red's weakness, not white's.... except red has grown past this weakness in the form of impulsive draw and
Outpost Siege effects.
See
red's article.
Red's greatest weakness is an unwillingness to think long-term. Red is very short-sighted, trying to accomplish what it wants right now and seldom thinking of the ramifications of its actions. Red often puts all its eggs in one basket, and if that plan doesn't work out, red can easily get itself in trouble.