Perhaps it’s easier to imagine/create/use a weapon in a LD when you are either comfortable with it in RL or you train yourself to be comfortable with in LD’s. When you are in need of a dream weapon, you are likely in a fearful/stressful situation. Therefore, you are at a bit of a disadvantage, and that’s why most people end up abandoning their attempts to conjure what they really want, and settle for what’s easy.
Many times, one of first things I do when I realize I’m dreaming is arm myself. Depending on the overall atmosphere of the dream, I either carry a curved knife (in my right hand, or attached to my right hip for easy access) or I conjure a sort of energy that protects my body. The energy thing is easy, because I do a lot of meditating, etc. in RL. The knife is easy because I found it in a LD years ago, and usually have no problem making it appear at will. I’ve tried several times to conjure 2 knives–one for each hand. But I’m right-handed in RL and that seems to carryover and handicap me in LD’s, so I find myself struggling to create a left-handed knife. Unfortunately, unlike the previous poster, I’ve never thought about conjuring dildo-wearing dogs…