Generally what you'd be aiming for is a suitable amount of WD (wind down) time which could be sitting or standing holding him and either shush/patting or even a little rocking if that's what calms him before putting down in the cot and once in the cot just a little pat or firm hand say goodnight and leave. And he would be happy to settle himself and go to sleep. That's the goal.
The WD time for LOs can vary. Some LOs do need longer, some hate a long WD and it is down to learning your LO's character and personality which can take time. My own LO screamed his head off if I tried a long WD and I learned to make it short, quick nappy change, into bedroom, one song whilst holding (dancing/rocking) then into cot and he'd just smile before I left the room then self settle. That doesn't mean it was like that 100% of the time, LO have all sorts of difficulty with developmental leaps, routine changes, nap drops, teething etc etc and through those times they can need more help (sometimes an hour for me) but these are generally phases you get through before returning to normality and independence again.
5 - 25 mins to get him to sleep does not sound bad at all however the crying is probably not very nice.
have you tried putting him down a bit sooner and keeping your hands on him in the cot? Either patting or making a small rocking motion using a firm hand if he is used to rocking. Maybe try, see what happens. Obviously if he continues to cry hard pick up and comfort him.
Could you record your EASY time and post them so we can have a look please?