You may be participating in brawls with a guild you have joined recently and notice that after completion of the combat stage, you have received fewer merits than other members of your guild. When you first join a guild, there is a 7 day probationary period wherein a few limitations are placed on players.
New guild members cannot contribute their battles to help level up their guild lodge, receive the RP bonuses from the lodge, nor are they able to receive the benefits from their guild store until that 7 day window is over. This will include the merit % increase from a guild's store as well as the discounts applied to the guild store.
Because of this, you may find your guildmates receiving more merits than you. If you check your guild's store level, you should also find that the merits bonus (seen below) for that level will account for this discrepancy. This limitation will immediately be lifted upon completion of that 7 day period, and your merit rewards as well as battle contributions will now be handled the same as your other guildmates.