While many of the larger creatures that you might typically associate with green cards are missing, having been instead shifted to powerful artifact creatures, theres still plenty to be impressed with in The Brothers War
ACR SET REVIEW: RED Slicer has proven to be a formidable option to get life totals moving, even seeing play at cEDH tables
Personally however, I think the Grey and Back imprinted theory is probably correct
It can only put +1/+1 counters on artifact creatures and it can only put charge counters on non-creature artifacts
7 Gimmick Puppet Dreary Doll Too Bloody For The TCG There's nothing scarier than a haunted children's toy
If your collection is very high value, or contains high value cards such as Power 9, dual lands, Reserved List cards, serialized cards, etc., you should contact a vendor such as AncestralMTG that specializes in high end cards and collections