At best youll deprive them of a few key resources, at worst (and more often than not), youll make their deck more consistent by trimming the fat
Every Commander set has at least one card that catches a wide swath of the communitys attention and [casthaven]Mairsil, the Pretender[/casthaven] seems to be that card
When this Elesh Norn comes into play, it not only gives your creatures +2/+2, but reduces your opponents creatures by -2/-2
If you want to go the creature route, Metalwork Colossus, Phyrexian Triniform, Platinum Emperion, and Inkwell Leviathan are all top-notch powerhouses that Sharuum can drop on the field to establish an instant board presence
Here we have a Grusilda, Monster Mash deck that enjoys mashing your dorks together, but not mashing your budget