The court itself uses the word "clerkship":
"The Tribunal has no specific limit to the number of externs (or interns if they are earning credit for their clerkship at their respective law schools) that are hired for a clerkship" (See http://www.michigan.gov/taxtrib/0,1607,7-187-39032_39706-139276--,00.html)
I'm not suggesting that your court is unethical. I'm suggesting that the person who set up the internship/externship program at the Michigan Tax Tribunal is too f-ing ignorant to distinguish between an internship or externship and a clerkship. Although their ignorance should neither be encouraged or perpetuated, it is not unethical. Law firms that blatantly misrepresent the truth are unethical.
They do when firms call the summer job with a judge a "clerkship" or call judicial interns and externs "judicial law clerks", "clerks", or "judicial clerks".
No one here used the offending term "clerkship" until you did, although a website creator did also.
The website creator even added a few more terms. But you were already offended before visiting the website. Correct? I used the term "clerk." And I used it here on a law student forum.
I'm not aware of any firm which has used the above website to boost the reputation of associates and you have not mentioned any. But if I understand you correctly, you say law firms are misrepresenting their associates to clients. I would agree with you that it is unethical.
Does the mere use of "clerk" accomplish that? I don't think it does. "Clerkship" is on a different footing and if not used carefully it is misleading.