Betatest03 is correct. The Statue of Zues, Cathedral of Aachen, and Castle del Monte can only boost the attack and defense of the attacking army while Saint Basil and Deal Castle only boost the attack and defense of the defensive army. The latter two GBs plus the Observatory also boost the attack and defense of defending armies in Guild versus Guild, while the Monastery and Watchfire only boost the defense of the defending army in PvP (neighborhood battles). There is no bug here, and everything is working as intended.