My 36” lightweight rollomatic with a 114 link Oregon skip chain weighs 5 lbs 6 oz almost a full pound less than the 28” OEM bar and chain—I know because I weighed each of them on a postal scale.
The 36 will cut through wet oak without breaking a sweat.
Admittedly I find I can get most everything I need done with an 18 inch bar but to answer your question a 36 bar works just fine and is also now endorsed by Stihl despite it not being original equipment when the saw first rolled out.