Motions for new trial are hard to obtain...depending on the judge you are in front of.  Some judges will hand them out like candy...while others will want good information to explain why you didn't handle the case properly the first time.  A majority of the judges fall into the latter (tougher) category.  If the attorney that you have hired believes the chances are slim because you have a judge that is in the tougher category, then you are better off putting your funds to use in a modification action.