How much focus should be given to Siphoning Strike while clearing camps on Jungle Nasus

As a Nasus jungler, I can't decide what is more important.

Should I not use E for the weaker camps and try Q-last-hit even the small monsters or should I just Q-last-hit what I can (usually the biggest monster), but always use E and smite?

To clarify, I'm asking what solution is better in the long run in terms of making me generally stronger in team fights under normal circumstances.

Solution 1:

Use Q to last-hit as much as possible, but not at the expense of speed (much, a second or two is probably ok). The faster you clear the jungle, the more experience you've earned, and the more gold, which leads to potency faster than Q-stacking alone.

Additionally, you'll be able to assist your allies more, possibly picking up Q-stacks from lane minions and enemy champions, as well as forcing/protecting turrets and dragons.