There is a range of glass designed by Michael Powolny for Loetz.
There are follow on productions by Wetz, Kralik and others that look similar to Tango but are not and they never called it so.
To heap the same name on to all glass similar causes confusion. It would best be called Tango Style.
Using the same name leads to such instances as follows and that is the danger of comparing "similar" to actual.
. Ref. loetz.com Michael Powolny:
"The 2009 Herman Spaink book 'Loetz Tango Glass' includes many (very good) photos of glass which the author wrongly attributes to Powolny and/or Loetz. This has caused huge confusion in the art glass world; indeed, this book is probably the single biggest source of Loetz misattributions. Just today I searched ebay.com for 'loetz tango'. I had 71 hits, many including Powolny in the description, and much more than half were not made by Loetz and almost all had no connection whatsoever to Powolny. Several of those that do look like Loetz products in the photos must be approached with care – Vienna's many souvenir shops are full of passable modern reproductions of the genuine Powolny designs for Loetz, and these sometimes find their way to eBay or to auctions described as Loetz originals"