Yeah, you are right about the "experimentalist" stuff.
As for the fact of "they" and "be" lumped togheter in the same sentence, it would be wrong by comtemporary standards. That´s right.
Yet, it seems that in academical texts and old English (meaning Shakesperean texts, religious texts etc...) it can be put togheter, no problem with grammar (of the time, I mean).
In this vein, nobody debates the grammar of:
Bible (KJV version, to illustrate.)
Romans 7:1 Know ye not, brethren, (for I speak to them that know the law,) how that the law hath dominion over a man as long as he liveth?
2 For the woman which hath an husband is bound by the law to her husband so long as he liveth; but if the husband be dead, she is loosed from the law of her husband.
3 So then if, while her husband liveth, she be married to another man, she shall be called an adulteress: but if her husband be dead, she is free from that law; so that she is no adulteress, though she be married to another man
In the NASB you can see the verse 3 corrected...
3 So then, if while her husband is living she is joined to another man, she shall be called an adulteress; but if her husband dies, she is free from the law, so that she is not an adulteress though she is joined to another man
both here for comparisonhttp://onlineparallelbible.com/romans/7.htm
In the same vein, nobody disputes Shakespeare´s quote grammar.'Though she be but little, she is fierce!'
(she is short (mignon/a little thing), but she is brave!)http://www.biblestudytools.com/commenta ... ohn/8.html
"according to your own tradition will I judge you; if you are without sin, stand to the charge, and let the adulteress be executed; but if not, though she be guilty, while you that present her are equally so, according to your own rule she shall be free.
So, the ver "to be" in this cases is now "is" to ''she"/"are" to "they" (BE traduzido: seja/esteja/sejam/estejam), yet it seems it was used equally in plural or singular forms. So it could be "they...be" or "she/he...be" (in the ancient grammar way, of course)