Both would be good team builds.Nature has heals which would help more on the lower lvls and trials.I would take glue arrow because it has many uses.When I teamed we would pull more than one mob so I could slow
one with Arctic Air and the other with glue arrow,which also worked in trials.Frostbite and Entangling Aura are
not going to play well with Ice Slick.Trick Arrow will work really well because Ice Slick+Disruption Arrow+Acid Arrow+Poison Gas Arrow then followed by Oil Slick Arrow+EMP Arrow then Ice Slick again means teams will
not have to worry much about return attacks(even blasters).Nature would up close more often where as Trick Arrow and Ice would be at range.
I would make both and will if we ever get the game back.I am going to try to give every combo a try just so I can see for myself what works.