And.... your point is?
Although the article written in the link is correct, of sorts, it is also incorrect.
There are such things as family crests; and seen often on items of silver carrying two crests (often explained as an example of two persons joining in marriage). But I then pose the question...how many women carry their own arms?
The article briefly and thinly talks about the celtic side of "permissions" to use family crests. One assumes it excludes the English. However, the Royal Collage of Arms rules are quite strict, whereas an applications to Lord Lyons (Scotland) may give you a different outcome.
The article points out the methods of an older regime; but times have changed and permissions can be granted to use Family Crests.
Further, my reply to the OP was a kind reassurance. There are several coats of arms which carry a crest the same as many other coats of arms, and it is nice to see a crest which can be attributed to just one blokes coats of arms.
As for the latter part of this article which claims you are exempt from registering arms, and that designing your own crest is acceptable, then that is satisfactory as well. However, it probably will not have any historic significance and will definitately not relate to any of the works as listed in Fairbairns.