Subwoofer Question

With the help of many in this community I have put together a two channel system I am very happy with. I am a proponent of both vinyl and streaming so the setup is as follows:

Plinius Hiato Integrated Amp
Dynaudio Contour S 3.4LE speakers
Martin Logan Balance Force 210 sub
Dr. Feickert Volare turntable with Jelco tonearm and Lyra Delos MC cartridge
Innuos Zenith server
Lumin T2 streamer/dac
Bryston CD player (don’t use much)
Analysis plus copper speaker cable and interconnects 

The ML sub was something I bought to augment a pair of Magnepan 1.6 speakers before I revamped everything. Quite frankly I didn’t know what I was doing; the thing is huge, difficult to position and I’m not sure I’m getting the bang for my buck.  It gives a boom for sure but is a bit muddy and I don’t have a lot of good positioning options. It just feels like it is too much and not a fit with everything else. My listening room is fairly small and I sit about 10-12 feet away from the speakers.  Because this hobby induces a never ending need to upgrade/tweak I have been thinking about replacing the ML with two smaller subs such as the REL T/7i’s or T/9i.  I do like bass so I feel I need/want a sub. In my research I also keep reading that subs make the midrange sound better if you have the right setup.
Am I crazy? Would very much appreciate thoughts and opinions.

thanks