Given the constraints of reaching orbit, surviving reentry, and cross-range capabilities there's a general lack of variability in spacecraft design. Some of us are old enough to remember promotional/propaganda materials concerning the original Boeing X-20 "Dyna-Soar" engineering designs from the
1950s which strongly resemble the subsequent US Space Shuttle, the Soviet Buran orbiter, and the Boeing X-37B and X-40:
<https://en.wikipedia.org/wiki/Boeing_X-20_Dyna-Soar>