As Semi said, you should be okay. After you get everything together, including the tensioner, you can rotate the engine by hand and make sure the marks land where they should be.I turned the engine over by hand without the cam tensioner installed. The chain binded somewhere and I think it skipped a few teeth as well
Just fyi, I did the same thing but only because my factory manual specifically states to retract the tensioner and THEN rotate! I still had my cams in but it jumped a tooth and never looked right after that. I got real good at removing and installing the cam cover as I tried different cam positions!