If we're combining age, commitment to the club and ability, you're probably right.
Pogba is a better player but his commitment is an issue. De Gea has been a better player although is on the decline now & is another who has looked to leave in the past.
Rashford, Martial and Wan-Bissaka are our most important/valuable players right now.
Given Rasfords physicality and drive I think he can be a Rooney to Greenwood's Ronaldo in the sense that Greenwood will be the classier player and finisher but Rashford will make it possible with his qualities
Other way around for me, Rashford=Ronaldo, Greenwood=Rooney
Before the mob start I'm not saying they are as good as them.
Ronaldo was not a fantastic finisher at 21-22, he missed a lot of chances, similar to Rashford now. In fact, his breakout season was 2006-07 when he hit 23 goals from the wing, he was 21-22 that season. Rashford is already on 16 this season, so he should hit that mark or perhaps even beat it. I'm by no means saying Rashford will be anything close to Ronaldo's level, but there are similarities statistically between them at the same age. Rashford seems to be beginning to become a good header of the ball, another thing Ronaldo developed at from 21-22 onwards.
If you look at their PL records in full seasons when they were the same age
Ronaldo at age 18-19 - apps: 29, goals: 4
Rashford at age 18-19 - apps: 32, goals: 5
Ronaldo at age 19-20 - apps: 33, goals: 5
Rashford at age 19-20 - apps: 35, goals: 7
Ronaldo at age 20-21 - apps: 33, goals: 9
Rashford at age 20-21 - apps: 33, goals 10
Ronaldo at age 21-22 - apps: 34, goals: 17
Rashford at age 21-22 (so far) - apps: 20, goals: 12
It's undeniable that it's a strikingly similar record.