I've played the meditation amulet 2 sbp / yard build and it works out pretty nice for me.
I honestly tend to find myself running out of space for zone exclusive conjurations.
An running 3 spawn points takes some getting used to. CY / Forge / Barraks
Where I find a flaw in this build is the lack of your armory which in creature heavy play is VITAL.
2 armor / 1 piece orc butcher are LEGIT.
3 armor / 5 melee / 1 piece VET butchers from what most opponents say need to die sooner rather than later!
As a warlord you can run out of zones to put down your stuff and this is really the biggest drawback. a CY stocking up on mana is not a problem at all because you should have plenty of stuff you want to use. Armory, Wall of Earth/Stone/Iron/Pikes, Altar of Iron Guard, Balista, Hammer, Altar of Carnage.
These are not things you are casting at start of match so that 4 or 5 mana saved up really does help. You also get mana for destroying constructs equal to their level.
An honestly who is going to kill a construction yard...
I think it should also work for earth Terrains but that is another battle...A free grunt and 1 butcher a turn is a problem for most builds. Toss in a good standard carry and you have a legit little army. I've used Panzer guards in the past because they have a dodge.
I've been thinking a Knight of Westlock might be a good invest though for that purpose.