Common DC bus connection of the Lexium LXM32 and Altivar ATV320 is possible.
But there is more than one rating of difference between LXM32 drive and ATV32 drives. If all drives must deliver nominal power to their motors ,you have to supply drives on the AC network (big one can't supply other) as well. So, it should be better to add line chokes on ATV320 drives to compensate this difference (to avoid that small drive supplies the big one) and add 2 DC fuses per drive. In addition, to synchronize DC levels for LXM32 and ATV32, you have to use parameters (dCCC) on both to have same DC bus threshold (braking, etc...).