Trajectory: I'm not sure you really looked at this. Martial started okay (1 season), he largely dropped off other than 2019-20. Whereas Marcus has increased each year, with Martial only out preforming Marcus in two seasons (in goal terms). Martial has only once gone above 20 goals per season. One of the most glaring issues with Martial is his overall contribution tackles, blocked shots, interceptions. clearances, head clearances and assists. They aren't anywhere near what Marcus contributes. In other words, Martial scores less and contributes less defensively. We've seen that many times on the pitch. That trajectory hasn't changed for Martial it, it's his goals that have decreased or maybe hit his level of around 10 per season. That is his bread and butter for his job and he just doesn't do enough, never has really.
The comparison with Shaw is somewhat impossible to comprehend give Shaw had such a bad injury.