I think you rather want some mobility than the battalion. Furthermore i feel a single hero is risky for the mission where only heroes score. Evocators will delete what they touch, if they can get there, though.
At 2k i'd add more Sequitors, i personally like them in 10 strong squads as they tend to get all greatmaces in range while having enough sacrificial wounds to tank some serious damage. Add a castellant and translocation relictor for support and so.e mobility and you're good to go.