Vietnam war style stucture? What, because I feel that infantry Bns should have their own, man portable fire support?
OK I don't know anything about modern 60 mm mortars, but I do know about modern 5.56mm machine guns.....oh, yeah, they were replaced at section level with old fashioned , Vietnam era 7.62, because they lacked,range, and punch....just like we predicted in the 1980,s and 90,s.
40mm grenade launchers, and multi round 40mm would do at section level, leaving the MAN PORTABLE 81,s as the dedicated fire support at coy and bn level. Everything old is new again. Smart ronds and modern explosives in 81mm would have to have more punch than 60mm.
155,s as art back up with air support, and I'm a pretty confident patrol commander.