Mix of several camera quality in the same project

Here is the problem : I am trying to mix 2 different cameras (a high quality 24 MP hybrid camera and a lower quality 12 MP drone) in the same RC project.
When I use only the high quality hybrid camera, I have a good quality texturing but when I mix with the drone (about 25% of the aligned images come from the drone), I feel like the texturing is less good than with only the high quality hybrid camera.
How does the optimal texel size algorithm work ? Is this possible that adding lower quality images lower the texturing quality even on areas well covered by the high quality images ?

Hi Jonathan
Some screenshots would be great to understand the quality difference. It can be a misalignment issue or so, so without a screenshot it is hard to say what can be doneā€¦