Warriors with two weapons, Steel Shield and Silver bow OR Knight’s Sword. Archers are one of the few complete weapons, with great AoE, DPS, and range. Swordsmen have great mobility and equivalent spells to Cannon, Spirit Walk, etc. Stock them with generic (armored/hard) titanium armor and make two of each.
Optionally, a warmage. Have them use Fire Magic and Earth Magic, with Wall spells prepared to protect from opposing AoE attacks, and Pulsar spells to send out before the Wall spell. Stock them with generic (powerful/strong) sorcerer armor. Only one.
Also optionally, a healer. Stock them with spells like Surge and Ray, or a warrior with spells like Quickdraw and Rapid Fire. Give them the same armor as the warriors, and if anyone in your team can make Jewel Amulets, make one with Potency Musgravites. Protect them.
Getting six/five/four members into a server is easy, compared to more elaborate strike teams.
I’m a PvE player and made this for fun. If you do use it, let me know how it goes. If you use this to gank or witchhunt, I will be mildly displeased.