Switching

Could you confirm me? Can I enable MC-LAG on rwo EX switches and manage devices as one logical device?

I understand that It does.

Sort of no and yes, with no being the more exact answer.  Unlike VC, where there is one control plane, then the group of switches can be managed as 1.  In MC-LAG there are two distinct control planes, each managed separately.

Now, depending upon which exact product and which SW release is being used some new MC-LAG features such as config sync (https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/mc-lag-config-sync.html) and such allow MC-LAG to behave like VC with it's single management access, but there is still distinct and separate control planes in MC-LAG.

Good luck