Quote from Cide;225413:
then let's take crash shot with a far more down-to-earth and regular scenario: 4 spashed targets and 350 max damage.
(150%*4)350 = 2100. only a bit more than a magnum. this, however, is very variable as crash shot is situational, depending on the number of targets splashed. it can do anywhere from 525 implosion damage all the way up to 3150, if the maximum target number is hit. take this into account as well.
To make a comparison based on your example:
600 Int with r1 Blaze and a Combat Wand vs. 4 targets.
7200 dmg against a single target by knockdown, and 1600 dmg against the other 3. However, Blaze needs to be fully charged by 3 seconds. This is simply not possible if one was N+Blaze-ing a target as the stun of a Combat Wand is around 1.5 seconds. Which means if one was to solo practically with Blaze, it's going to be hard to pull off N+Blaze with a full charge, even with pets and such. Because of this, it's hard to gauge if Blaze should actually be 7200/1600 dmg in a regular situation. Also, at r1 Blaze, it uses up 66 Mana and 18 Stamina at full charge. Blaze also has a 4 second cooldown, and you can only use it within 170 range distance.
For your r1 Crash Shot example (not including master title), you only need 15 Stamina and 15 Mana to pull it off, and the range is dependent on the bow. It's 2100 dmg against initial target and 875 dmg against the 3 other monsters for only 15/15 cost and usually aggro-safe range. 2 second load plus around 3 second for aiming at max range, so that's 5 seconds per use.
In a regular situation like this:
Blaze
12000 total dmg
66 MP
7 seconds
The ratio of dmg-to-MP is
181.818_ in 7 seconds = 25.974 efficiency only if Blaze is fully charged for a solo N+Blaze, which is not possible.
Crash Shot
5600 total dmg
15 MP
5 seconds
The ratio of dmg-to-MP is
373.333_ in 5 seconds = 74.6666 efficiency
This is excluding the "danger close" nature of Blaze and its aggroing properties compared to Crash Shot's incomparably farther range and its aggroing properties. Also, not every mages carry a Combat Wand, compared to an archer carrying bows that aren't as differentiating.