Craft Edge

Can someone point me in the right direction I have read on here somewhere about regrouping in inkscape I understand that but how do you keep the regrouped items in the proper demention when I import them into scal at say 4 in. everything is that size and not in proportion I think someone explained this but at the time I didnt understand inkscape at all so did not know what they were talking about. also how do you know which clip art will break apart and which wont some I have tried dont have much detail when broken apart