Comparing to a smoke thrown with 150% skill, the 40mm smoke has 1-2 less seconds duration and -1 radius, it costs 5 times cheaper than the thrown version.
Do we ever need throwing skill? Why bother buying 250c nades when I can buy 5 40mm for the same price and get 4x duration? Nerf them, less radius, less duration (5-8 seconds total duration)
The incendiary are ok.