A lot has to do with how the "presets" are written and at what stage in the imaging processing pipeline they act upon the image. There can be a wide variation from one "preset" to the next. "Presets" are merely someone else's list of settings applied in a certain order determined by them when they recorded the preset.
"Presets" usually assume that the camera was set to expose for a "correct" average brightness and properly record the correct CT/WB for the lighting illuminating the scene. Most raw convertors by default set the initial exposure/brightness and CT/WB based on the CT/WB correction settings active in camera at the time the image was captured. Most other in camera settings are not necessarily duplicated by a third party raw conversion applications, but exposure and basic CT/WB usually are.
The presets then usually adjust things like exposure, contrast and/or response curves, color biases, etc. If they include an instruction to use "Auto WB" or to use a specific amount of exposure/brightness compensation, then any adjustments you have already made to the raw file are erased and overwritten by the preset. The color and contrast effects of the preset are mixed with whatever color cast and exposure biases the image already had when initially rendered by Lightroom before you made your adjustments.
If you first adjust things manually and then export as TIFF, those changes are "baked in" to the image and the preset acts upon the result of those adjustments, rather than erasing them and starting over. Again, depending on how the preset is written, some of the steps may not be applied to a TIFF in the same way they are applied to a raw file, because the TIFF doesn't have all of the information contained in the raw file.
