I'd replace the cans with more Deffkoptas or another squad of Boys in a Trukk, so your army all goes forward as one. I guess there's an arguement for having the Kans sit in your DZ and protect the Grots if anything threatens them. But in all honesty if anything so much as sneezes at Grots they're done for, so you'd be better off snagging other objectives with your Trukks and Wagons full of Boyz rather than protecting the Grots.
I'd drop the Buzzsaws on the Deffkoptas too, you don't want Initiative 2 models in at tiny unit sizes in combat, not usually anyway. Depending on the unit size you could use the points for 1-2 more Meganobz.
I'm a bit of a rookie with Orks though, so I'm probably wrong.