Re: what to do with sirrush ?
 

IMO you really need a minor Nature bless to get full benefit of the Sirrush. Like many have already mentioned, mix them with other units. What has been left unsaid (I think), is why you should do it.

The reason is twofold:

1) The Sirrush doesn't get swarmed as he is protected by the smaller beings
2) The Sirrush eats anything dangerous to the smaller beings in the unit