While I'll agree that Doom Patrol, mid-sixties Challengers, Metamorpho to an extent, and some superficialities of the Legion strip bore some resemblance to Marvel (especially Doom Patrol), I'm not sure that's what Doc asked.

Because what was notable about Doom Patrol et al was that they were very different from the characteristics of Marvel that caused it to dominate the market: cross-title continuity, heroes with emotional and psychological problems as a given rather than as an exception, and long-term storylines.

Not to mention, DC failed in those strips, since they were all cancelled well before 1969 (even Legion was demoted from the lead in Adventure to the back-up in Action before disappearing altogether for a few years there).