No, I'm not. I'm telling you flat out that a 40k Ward would be RIDICULOUSLY overpowered.
You have to decide what problem you think you are trying to get addressed.
If you are trying to make Shaman better at healing a group, great. It's a worthy cause. Increasing the size of their Group Ward is not the way to do it, and frankly you'll never get any support for it. With a Ward that big why would you even take other healers? You certainly wouldn't need them.
The alternative of course would be to simply make the mobs hit harder. That would not go well. Raid mobs hitting for 30k regularly? That's not very attractive. It would also mean that group content would be COMPLETELY trivial for a Shaman to SOLO. I mean, why not just put in /iddqd?
The mechanic of the Group Ward is the reason Shaman are weak at healing (or protecting from harm) an entire group. If you want to fix that you need to change the mechanic. Having some sort of "stancing" for Wards would be a huge step in the correct direction. Anything else would require re-balacing of all the existing content.