The lensatic compass is really an "engineering" compass. It was designed for survey work rather than land navigation. You can use them in preferance to a Silva 1-2-3 type baseplate, but they do require a much higher standard of navigational skill. That, in and of itself is a good reason for buying a basic model and learning how to use it.
One issue you will have is the need to orientate a map before obtaining a bearing and you will need a notepad and pencil to note the infomation.
You will have to be very careful to ensure that there are no metal objects near the map & compass when working out your rout.
As a practical matter, you are better using a silva compass card to derive bearing from the map. Which brings us back to the 1-2-3 system.