Importing seperately is a good idea.For Max 9 (reading from different threads),using .FBX works fine.You are talking about 70 models,that's a lot;but for a better results,I will export seperate models from each category of model set and then duplicate in WED to make up(if needed) instead of trying to export 70 models individually.Importing as .MDL is possible but not 70 models,you will quickly realize why.