A forward in a relegation-threatened team is measured by the same goal column as a forward in a title-winning one. The chances arriving in front of him are not remotely comparable, and rankings rarely account for it.
The supply is different in volume and quality
A weak team spends less time in the opposition half, creates fewer entries into the penalty area, and produces fewer clear sights of goal per match.
The chances that do arrive tend to come from transitions and from long balls rather than from cutbacks and rehearsed patterns.
So the striker is finishing a harder set of opportunities, fewer times, with less service designed around what he does well.
His job is often not scoring
Forwards in struggling teams are frequently asked to hold the ball alone, to relieve pressure and to run channels so the defence can move up.
Those tasks put him facing his own goal with defenders around him, which is the opposite of the position a goalscorer needs to occupy.
Judging his goal return without acknowledging the role measures how well he performed a job he was not given.
Chance-quality measures help but do not solve it
Comparing goals against the quality of chances received corrects for the supply, and it usually shows these forwards performing better than their totals suggest.
The correction still misses everything the player did that never produced a shot, which for this role is most of his contribution.
It also rests on a smaller number of chances, so the confidence around the estimate is wider precisely where it matters most.
Watching for the transfer signal
The practical test the game applies is what happens when such a forward joins a stronger side, and the results split fairly evenly.
Some flourish immediately, because the qualities that produced goals from poor service work better with good service.
Others do not, usually because their value lay in physical duels and running rather than in the penalty-box movement a dominant team requires.
A defensible way to rank them
The honest approach is to rank on what the player did relative to the chances he had, and to state the uncertainty rather than hide it.
Reporting the role alongside the number costs a sentence and prevents the most common misreading of these lists.
Anything more confident than that is asserting knowledge about how a player would perform in a situation nobody has yet observed him in.