You should wait for test-server to see the tweaks before we can talk about characters.
Originally, DL was able to have 80 members in guild while other chars 40. We've reduced this big gap to match our CS balance. The reason while we still kept a small advantage for the DL-GM is simply CS related. We are only "forcing" people who wants to compete for CS to have a GM-DL, because it is the only GM char able to properly register the crown. Playing at CS without DL-GM means a big disadvantage for the rest of the guild, which we wanted to avoid. More than that, it is on the DL character fantasy to be the "Lord" of the guilds.
In parallel, whoever doesn't care about CS can still make Guild with 20 people (more than enough for "casuals"), and also having the alliance possibility (+20/25 members).
I won't say that I am not open to increase the number to 25 for all chars, but in my opinion it does really make sense to keep it as it is, unless you can prove me wrong.