creating new role for players is it worth the effort?

[ZeekLTK]

I used to think having players capable of playing in multiple positions is useful. However, I've come to learn that multi-position players won't be as good as single positioned ones.
For instance, a DC/DL at 120% is made up of attributes for both positions. That means, the player may have 110% tackling (DC), 140% crossing (DL), 130% strength (DC), 90% speed, etc.
On the other hand, a pure DC at 120% will have high stats that are limited just to its single position, like tackling, marking, strength. Its rating won't be boosted by DL stats like crossing, speed, aggression, etc. I hope I'm explaining it well.

It makes sense, but some times you just need the versatility. I like having players who are DC/DL or DC/DR because then I can easily switch between formations to either a DL-DC-DC-DR backline, or just DC-DC-DC. And then when I'm using DC-DC-DC I don't feel like I'm wasting roster spots by carrying a DR or DL who won't even be used in certain matches.

Same with AML and AMR. I don't really use formations that have those positions usually, but sometimes it's nice to surprise an opponent with them. Having a ML/AML allows me to do that, whereas if I just had one player who was ML and another who was AML, the AML guy would only play like 5 games a season or something, which seems like a waste to invest in that. Instead, I can have the ML/AML guy play EVERY game, even if like 5 games are AML and the rest are ML. And even if I decide to use him as an AML in a game, if it's not working out, I can just move him back to ML without having to use a substitution.

I typically just buy multi-position players though, as it's tough to train without them falling behind. I don't think you should have them set to learn the new position gradually (like as the season progresses), I think you need to use a bunch of greens to do intense training sessions, heal them back up, and then keep going, all in one sitting. Then they learn the new position quickly and then you can focus on improving their stars for the rest of the season.