There are plenty of such artist tags. boku is another. I usually just check them post by post and try to figure out how they should actually be tagged, when I can be bothered to do it.
Your tag has multiple aliases in current use. poko, poco_(asahiage) and asahiage. We could settle on “poco_(asahiage)”. It should be possible to alias “asahiage” into it, but “poko” might need some cleaning up before an alias can be made.
I think we had a good discussion/solution in this thread, which you are also suggesting: http://chan.sankakucomplex.com/forum/show/1276
The mainproblem is the timeconsuming part of checking all pictures via http://iqdb.org/
At the moment I can't motivate myself to do it. I'm still hoping for System to jump in and safe the day with a fancy script/thingy.
You can't safely make aliases of such generic names or nouns as they will tend to auto-populate with mixed junk unless constantly monitored. A two kana Japanese name is likely to have all kinds of homophones extant and likely to become extant.

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Steinkauz
1 year agoWeak artist tags and the mess after
While cleaning up some duplicates, I stumpled other this post:
http://chan.sankakucomplex.com/post/show/902315
A short glance at the artist poko showed me how messy this tag was. There are sure more than one poko here, and it's a pain in the arse to clean it up without spending a ton of time.
What I would do, because there is still a working pixiv link to his profile:
1. Get all pixiv submissions (32) of the artist.
2. Check which one exist on the channel.
3. Add them under a new arist.
And here comes the problem(s):
1. Is it legit? He may have submissions somewhere else.
2. If it's legit, an automatic process would be great to do it with other messy (artist) tags, but I lack the possibilites to do/create it.
3. This method wouldn't work with bad_id artists.
Advises needed.