not sure about the warshrine. All your other units are way faster so I think it might get useless by being out of range. Blocks of 40 marauders are ridiculously cheap and could be a second wave to go with the warshrine, ideal objective holders/ terrain deniers, if you want to play it?
I would take flails on the knights. Double wounding and rend is powerful even if it is only on the charge. Retreat and charge with another unit if necessary.
The ruinbringer warband might be a bit expensive for what it does. You could take more knights or a lord on manticore instead? or marauders?
Or scrap the warshrine and battalion and take 2 giants for a bit of fun