Interested in subscribing to iTunes Match but concerned about number of devices

Question

My family and I all share 1 iTunes library. All purchases are made using the same AppleID account. We currently have 17 apple devices and will most likely be adding more with Xmas coming up next month. We are interested in subscribing to iTunes Match. Can / How do we use iTunes Match across all these devices? I would guess that there are many family's out there like mine where each person has an iPhone, computer & iPad. Limiting iTunes Match to 10 devices will not work, especially if you have a large family. Hopefully I'm not understanding it correctly and someone is able to assist.
Thank you.

Answer 1

This is in facto, too dificult.... Surely I am missing somethin...
http://support.apple.com/kb/HT1420?viewlocale=en_US&locale=en_US
" Authorizing and deauthorizing a computer allows you to manage which computers can sync or use apps, audiobooks, books, music, movies, or other content you've purchased from the iTunes Store.
You can use or sync your purchases from the iTunes Store on up to five different computers (these can be any mix of Macintosh or Windows-compatible computers). When you sync or play an item you've purchased, your computer is "authorized" for purchase using your Apple ID."
OK
Then.....
http://support.apple.com/kb/HT4914
"vWhen you subscribe to or enable iTunes Match, your device or computer will be associated with your Apple ID. Your Apple ID can have up to 10 devices and computers (combined) associated with it. For more information about associating devices and computers to an Apple ID, see this article. "
And "see this article" here link directs us to:
"Your Apple ID can have up to 10 devices and computers (combined) associated with it. Each computer must also be authorized using the same Apple ID. Once a device or computer is associated with your Apple ID, you cannot associate that device or computer with another Apple ID for 90 days. "
What is then the "truth"? When I try to add another computer it seems (previous post) that the first is true (I only have 7 devices associated with my Apple ID). Not the second.
Cheers
Jorge Lampreia