Yes Smokey. In the most usual situation, the first L or NDB marks the FAF and second one marks the MAPt. There can be slight variations on this but the fact remains that, if the first facility marks the FAF, the procedure protection area can be made smaller by virture of the overlapping final segment protection areas. This clearly indicates that the procedure should be flown using 2 ADFs.
Pilots really need to think about that when flying a Twin NDB or Twin Locator approach using just the one ADF. I suspect that the procedure designer got overridden on this, by people further up the food chain who, in turn, were being hassled by elements of the industry. It wouldn't be the first time that this sort of thing has happened.
I suppose that the practicality of the situation is that, as long as the two facilities are within about 5 miles of each other, there's very little risk of an aircraft leaving the protection area. Of course, if either of the facilities is a bit weak in power or earth mat, or there are CBs around, I reckon that all bets are off.