No, they wanted tp make sure it was different enough from the Franz Joseph single nacelle Federation Scout and Destroyer designs in the STAR TREK Technical Manual - which Paramount gave Franz Joseph full copyright over meaning IF they used one of the design verbatim, they'd have to pay his Estate royalties, or face a possible lawsuit.
I’m aware of the FJ stuff. But I’m pretty sure that making the pylon without the gap wouldn’t have been problematic. Other than the general shape, the Archer looks nothing like the scout/destroyer. That’s like saying that the producers of TNG would get in trouble because the future Enterprise-D from AGT has three nacelles like the Federation class.
And didn’t Doug Drexler make artwork of the Ptolemy class tugs in one of the SOTL calendars?