Over a dozen isnt short for the era. More than MT or TNE.T20 proved to be too much effort for a one man shop, and sputtered out after a short line of books. SJG hired Loren and began GT in a once again empty field. Marc was writing what would become T5, but that effort would prove to be a decade long work.
I don't expect "5e" to be my cuppa, but I am hoping it has good art.
And T5 is more than 20 years effort.