Both, really. JNT's cosutming choices were notably known for their standardized look. Doctors 4-7 under his tenure basically stuck to one solid look with relatively minor variations (5 changed the design of his sweater once, 6 had different waistcoats and cat pins, 7 changed his coat) while the Doctor prior to that had more significant variations (notably 3 and 4 with several different coats, accessories, etc.).
JNT considered the costumes "uniforms," and he thought the characters would be easier to merchandise if they had a constant look.