Rather than making IT larger than DO, please try some versions with "DO" and "IT" in equal font size.
Also, let's move away from the arrow concept. Other ideas for "do it" or "get it done" or "work" might be a symbol/icon for a hand, a gear, a hammer, or something different. Thanks!!
My main concern is people seeing the new logo and understanding that it connects to the old - perhaps a good test would be to put both the old unconsulting logo next to your new ideas and see if they are congruent. I could see literally doing this on some of my sales collateral - where the upper left of a document has the old unconsulting.com logo and the upper right has the new logo.
As I start the transition to the new brand, Do It Marketing might initially become a service offering of unconsulting. So both logos need to look like they "fit"
I understand that this kind of rebranding effort is among the hardest for designers because you may feel you have one hand tied behind your back - but within defined limits, there is immense creative freedom!!