That is true. However, they seem to have a great talent. I mean looking at Future Trunks, who was nearly matching SSJ3 Goku in the DBS Manga with Super Saiyan 2 (Full Power probably), I can fairly say Present Trunks can do the same. If they were trained properly , I can see them surpassing Goku, Vegeta, and even Gohan.
Only reason why Gohan could be the strongest is because of his hidden power.
Future Trunks after much experience with ssj2, managed to go near ssj3 lvl as ssj2 in the manga indeed. In the anime he got rekt ezmode though.
However Vegeta was able to go ssj3 lvl as ssj2 as well when Bulma got slapped by Beerus. Its not something totally unique that we havent seen before and I dont consider future Trunks=Trunks (more on that later).
Gohan seemed to have more talent to grow in power in general compared to Goku and Vegeta, regardless of the subject hidden power.
Future Trunks wasnt all that special power growth wise as
Gohan as 11 year old surpassed him.
Gohan surpassed him (and also Goku and Vegeta) already as just ssj1 even and especially as ssj2.
Future Trunks has shown something impressive compared to the other known saiyans when he transformed into the new ssjrage transformation.
Something gained under the intense emotion of being called sinner and him being called the reason why his timeline was being screwed by the Zamasus. This while he was doing his best to protect, yet suddenly he is called the reason for the destruction. No dragonballs to fix things. No sensubeans. All his timeline family dead. Even Ssjblue Goku and Vegeta (father) from a different timeline struggling in being able to help his timeline out. All the people and the world he cares for in danger.
No method around to overcome the threat.
Yeah ssjrage is getting summoned out of an extreme situation to say the least.
I dont see our timeline Trunks unleashing super saiyan rage as its not likely that he will go through the same intensity and desperation as future Trunks did. Besides they are not the same Trunks.
They grew up differently and were born into different worlds.
Vegeta in our timeline f.e. had seen 2 ssj (future Trunks and Goku) which could be a change among other changes that influenced how Trunks was conceived and turned out compared to future Trunks.
Goten doesnt seem very different power growth talent wise than Trunks so I dont scale him above Goku and Vegeta either.
If all would focus the same on becoming better it would imo probably in the end be:
1.Gohan.
2.Goku/Vegeta.
3.Trunks/Goten.
However Gohan slacked in peacetime, went scholar and fell far behind Goku and Vegeta.
Trunks and Goten can often be just kids and dont carry the pressure of being the ones on whos shoulders the well being of the world rests.
Excluding the Gotenks vs Buu part of dbz.
Goten and Trunks going ssj so easily could have to do with the lvl their fathers were at when Trunks/Goten were conceived (power wise/ssj wise/near ssj wise). So I dont necessarily consider that a sign from Trunks/Goten for being talented.
Pan just started flying yet Goten needed to be taught by Gohan.
If anything Pan has shown more natural talent.
Trunks and Goten could go and experienced up to ssj3 as fusion yet havent even managed ssj2 as individuals.
Sorry but I am not impressed by them.
Also as explained for me normal Trunks talent does not necessarily equal future Trunks. They are different versions of Trunks.
Not just age only imo.