To do this you need to things: a Muttawi'ah or two and a Maghariba Guard.
The Maghariba Guard is just the delivery mechanism. One that is pretty nasty. The real threat is the Muttawi'ah. 10 points get you two chain rifles with jammers and e/marat. Jammers are where it's at. On a successful WIP 15 roll, cause a model to become Irregular. Hit a member of the link team? He's out. Hit a Link Leader? Link's broken. Hit a LT? Loss of LT. No line of fire required and no dodge allowed without line of fire. With 10 points, I crippled a good portion of an Aleph army. First with the e/marat and then with the jammer. I didn't even use the bomb.
The setup is getting the Muttawi'ah to get to the Maghariba Guard and connect to it's two bracers.
Let's look at Impetuous:
|Move + Move|
|Move + Attack|
|Move + Climbing|
|Move + Dodge|
|Move + Jump|
|Move + Swim|
|Get Up + Move (whole MOV value)|
Despite being a short movement skill, Mount is not listed. Thus you can't use it with your Impetuous move. This means only a regular or irregular move may be used. This also means creating a setup where the Muttawi'ah can use their Impetuous move and be in position for their Irregular move. The best way to accomplish this is by deploying second but that isn't the best strategy to win and this trick really excels when you go first.
So what to do. I recommend you do two things. Deploy the Maghariba Guard the furthest forward. I deployed in the middle but you could easily pick a flank. Then deploy the Muttawi'ah behind it. Depending on how your opponent will deploy you will have one short MOV that will pull the Muttawi'ah back toward the guard if the first MOV takes them out of whack. You then have the Irregular MOV to get to the brace and mount up.
The Maghariba Guard is what you are going to move forward to get the Muttawi'ah in position. The Muttawi'ah will need to be in position and causing havoc before the start of the next turn. The main reason is because they will dismount on their Impetuous order. Having them in position means that they can cause more havoc. That's what they are there for.
Can you accomplish the same thing without the Maghariba Guard? Yes, it's difficult but not by much but now they have a TAG to worry about. I think I would worry about the TAG over 10 points of models.