...does that mean I can generate ONE LT order if I want to keep it a secret that e.g. Qiang Gao is my LT?
Unlike (most?) leveled skills, the different levels of Lieutenant don't have an "Optional" tag. The skill level rules just say: Unless otherwise stated, any numerical Level of a Special Skill automatically grants all lower Levels of the same Skill. For example, a Level 3 also grants Levels 1 and 2. Being able to choose which level of the skill to benefit from (like in AD or Camo) comes from the various levels being mutually exclusive in some manner. There's nothing mutually exclusive in Lieutenant. (The first bullet point in Lieutenant L2 is redundant. It's the same sort of thing that's written for Holoprojector L2 and L3, where the authors end up trying to explain how the multiple levels combine together...)
Holo2 has NFB, it has to have a lot of extra text circumventing that, although arguably the amount of extra text and they could just have skipped calling it combining the two skills and just straight up made Holoecho deploy as miniatures. Then there's Inferior Infiltration that relies on you ignoring the actual meaning of the words and going with common sense.
Right. The point is still that Holoprojector is mutually exclusive for one reason or the other. Both of the Lieutenant skills are obligatory, and don’t appear to mutually exclusive. So you can’t choose not to use Lieutenant L2. That’s in contrast to stuff like Strategos which has the Optional tag if you don’t want to use it.
No, but you can choose not to deploy using Inferior Infiltration skill by choosing to use a skill of a higher level optional skill even though you literally shouldn't be allowed to. Hence my question if this could also be applied to LT.