Okay, in response to my only reader I have figured the Cold One Riders for Hackett's M&M.
This is how I did it...
I took the saurus standard, 14 points, and modified it as follows. I felt the Cold One itself was comparable to a wolf so that placed the points of a wolf at 11 moving it to 25 points (wolf has a DF of 6 and a bite attack which costs 4 points and moves more than nine inches for a further 1 point...this matches Hackett's listing of it in th back of the book).
NEXT I added a lance to the saurus for 1 point. Now, I'm sure there is a reason for the lance as it has the same modifier to the target's defense as a sword which is free. I also realize the models actually have spears but they behave like lances for the purposes of play. We are up to 26 points.
Finally the cold ones can attack so this costs a further 10 points as a warrior on a mount that can fight also is an extra cost. We're up to 36 points...BUT WAIT! As only the highest DF between the mount and the rider is used (the 11 of the saurus) I decided that it would confer with a reference soldier... the orc.
An orc with spear, shield and chainmail is 11 point. An orc with axe, shield and chainmail mounted on a wolf is....21 points....WTF? This should be at least 11 plus 11 for the wolf PLUS 10 for the "Being mounted on a steed that fights" rule rounded up to 32 points...comparable with my calculations for the cold one riders.
This is what I think is going on... two of these costs are mutually exclusive; the cost of the mount and the rule regarding a mount that fights. As the defense factor of only the highest of the two is used, and it is likely that with common soldiers this will be the guy on the back of the mount, then the only combat value beint lent by the mount is it's single attack. Now, i'd say that there is some modification that could be done here as I believe he's not detailed the idea of warriors mounted on some very nasty monsters. Say a fantasy themed Arabian fighter on the back of a giant scorpion, which would have not one but two claw attacks. This should cost more than just 10 points. I think this can be solved one of two ways; either by paying the cost for "Being mounted on a steed taht fights" for each attack the steed gets, or by adding the cost of the extra attacks and grant that the 10 points pays for the first attack and the greater speed.
Re-thinking my saurus cold one riders they tip in at 25 points; 14 for how they were, 1 for the lance/spear, and 10 for the steed that fights. I feel it's really up to my idea of balance and fairness to assign a speed to the cold ones and i'll just put it at 14 as the wolves. This is really a good speed as I don't think they would be slower or faster but around teh same.
So, in finishing, the 8 cold one riders I have would tip in at 200 points, which is far less than their WHFB equivalents at 330 points.
Now I think there is a lot of room for gaming debate here as Hackett's rules are open to use and interpretation. For 200 points my eight models have an effective 24 "attacks", really a round of 10, a roudn of 6 and a round of 8. If you've played the rules this makes sense, otherwise I sound drunk.