The 16" tenon saw is big for the type of work I do. Depending on your work, it may be a one hit wonder for your workbench and then hardly used again. My 2 favorite saws are a 12" Bad Axe and a 14" Gramercy. Those handle almost all my backsaw needs.
There is no problem cutting those workbench tenons with a panel saw or handsaw, or any saw big enough to do the job. Worst case, get it started with a back saw and then switch to a panel saw to finish it off.