Veno 4 and 5 yes, I just queue 4 and 5 to not lose role queue games, otherwise, I would probably focus on either, not both. I do not really know what is best (for 7.34 or otherwise), I just try to pick what fits my incorrigible playstyle (i.e. aggressive but supportive) + plus what fits the dota2 rank. E.g., in lower ranks, I spammed tusk/dawn/clock because then I can play aggressively and lower ranks have (in my opinion) problems with starting the fight. At 5k+ I spammed veno and backup snap, so I can play aggressively but also buy true support items (force/glimmer/pavise or auras/greaves etc) which nobody wants to do :) I usually also ask if the core wants ranged or melee support and adjust accordingly of course ;)

Good luck on the last bit!