Yes he tended to overact with lesser actors but I aways saw him markedly improve when other more talented actors were in scenes with him. It’s as if he needed better talents in order to meter his own perfomances and tune his work to a much higher scale.
Watching his performance with scenes with Gary Lockwood in “Where no man has gone before...the 2nd Pilot episode and Shatner performs much better than one ever expects he could.
Gary Lockwood of course was in 2001 as Poole was definitely a bigger talent than that needed of a ST episode, but Shatner rises to meet the challenge. The one exchange between Lockwood, Nimoy and Shatner in the elevator where the captain was asked about the chess game, Nimoy complains about the illogical move, while the captain gazes at lockwood and does a quick “cut the throat” move signalling that he had beaten spock/nimoy, shows a bit of funny but subtle talent from Shatner one didn’t normally see from him. Lockwood I think brought that out of Shatner.
Lockwood would have made a hell of a captain but his talent was too big for the small screen, at least that particular show.
I saw it long ago. Pretty good, but an odd choice to shoot it in that language.
I did like Shatner in The Twilight Zone. He was in two episodes. The one in the diner with the devil fortune teller, and the "classic" one on a plane with gremlins. The former was well acted, the latter displayed his hamminess.
Star Trek 2 was his best acting.