in tikkanen's favour, i would argue that he might have been the best LW in the league for a few years of his edmonton prime
his first full year is 1987, where he's third team all-star behind goulet and robitaille, fifth in LW points (behind those two and mats naslund and walt poddubny), leads LWs in even strength scoring, ninth overall in ES points, follows it up with cup run where his offensive production was pedestrian but (i assume) his defensive contributions were high
1988, pretty far down the regular season LW scoring list, but gets put on the PP in the playoffs and explodes for 27 points in the cup run, which at the time was tied with mahovlich for third highest LW playoff point total ever (and still is seventh all time)
1989, his best offensive season (on a line with kurri and jimmy carson) but he missed thirteen games, second for the selke
1990, the regular season offence dips, but he's third for the selke again, but the cup run, oh my the cup run. five points in the last three games of the first round to come back from a 3-1 deficit, shuts down gretzky and outscores him four points to one in a sweep of LA, and ends up with 13 goals and 24 points while being the primary matchup guy against hawerchuk, then gretzky, then savard, then craig janney (which effectively shut down peak unstoppable cam neely). if tik had won the conn smythe i don't think people would have complained.
1991, another pedestrian offensive regular season, but another selke runner up. at this point there's no kurri and not a whole lot of messier. tikkanen is the main guy and this is his best playoff run. he basically singlehandedly wins game seven against the flames in the first round (hat trick, including the OT winner), outscores gretzky again in round two (on a line with klima and anatoli semenov—in a much closer series, tik assists on klima's game two OT winner, scores the game three OT winner, and scores the late third period tying goal to send it to OT). then the oilers run out of steam and get upset by the north stars in the third round.
so that's tikkanen's five year peak. it's a weak time for the LW position, coinciding with the end of goulet's prime and just the very beginning of kevin stevens's, and most people would call robitaille the clear best LW in the game those years. four first team all-stars and a second, never scored less than 45 goals or finished outside the top ten in goals. but if you said it was tikkanen i don't think you'd be wrong. three twenty-point playoff runs, and an arc where he transitions from basically prime alex burrows to by 1991 playoff fedorov.
all that said, you can't compare those five years, absolutely great and imo HHOF-worthy as they were, to these five years where mcdavid was the best player in the world. you just can't.