You can mix or max specialties from all the major US agencies. I have done them with SSI, SDI, PADI.
If you do AOW your Deep is only one dive. If you do the Deep specialty you should get more training and do at least two deep dives.
You can do Deep without the AOW. Some agencies will let you count AOW as part of the specialty but I never did that. If I was going to take a specialty I wanted to get a much out of it as possible so I never counted any of AOW as part of any of the specialties I took later.
In my own case I did Deep later when I needed it as part of DM and long after I had been routinely doing dives in the 80-100 ft range. So I did not get much out of that course other than a needed card but that may be the exception. One of my dive buddies is my old instructor who is also a Tech instructor so I have had lots of advice and training outside of the class room and the courses we did together often covered much more than the minimum.
If you do AOW your Deep is only one dive. If you do the Deep specialty you should get more training and do at least two deep dives.
You can do Deep without the AOW. Some agencies will let you count AOW as part of the specialty but I never did that. If I was going to take a specialty I wanted to get a much out of it as possible so I never counted any of AOW as part of any of the specialties I took later.
In my own case I did Deep later when I needed it as part of DM and long after I had been routinely doing dives in the 80-100 ft range. So I did not get much out of that course other than a needed card but that may be the exception. One of my dive buddies is my old instructor who is also a Tech instructor so I have had lots of advice and training outside of the class room and the courses we did together often covered much more than the minimum.