#001, EITHER OF THESE TWO or ANY OF THESE TWO

I get dailywritingtips from Dailywritingstips.com.

By and large, they are very useful.

I furnish below the link to a write-up titled: "Any vs. Either". http://www.dailywritingtips.com/any-vs-either/.

The piece is very good. It advised use of "either of these two instead of "

any of these two

", which is less apt when only two things are involved..

Yet, my mind has been lingering on, whether the Current Usage of English could be stretched to permit both the forms. I have used the Google Advanced Search, to find out the popularity of usage of both the forms. The following are the results:

1. "Either of these two" : 1,050,000 results.
2. "Any of these two" : 97,100 results.

BLOGGER'S VIEW
1. Obviously people are using the correct form.
2. Among the 97,100 results, there are reputed users like Universities, OWLs, Education Websites etc.

Among the Classic writers, I found Sir Walter Scot using the phrase "any of these two",in his work "The Heart of Mid-Lothian":

"Do you happen to know, sir," said Lady Staunton, "if any of these two lads, these young Butlers, I mean, show any turn for the army?"

QUESTION: WHY DO YOU SUPPORT THIS FLEXIBILITY?
A language develops its practices, structures, phrases etc. over a period of time; the time can be even Centuries. Flexible practices make a language easy to learn and use. This may be allowed as long as ambiguous or misleading meanings do not result.
E.g. : The pronoun "you" is used for singular number, two persons and any number of persons. Though there is some ambiguity, one word for all the numbers has come to stay.

The Sanskrit language employs the three number structure in forming sentences: singular, two-nos., plural (for more than two). Use of 'either' in English resembles the Sanskrit system. As English and Sanskrit both belong to Indo European group of languages, some remnants of the antiquity might have continued in English.