I thought that way too. For example, I see my Fi as the 'guiding light', the lantern I hold, but the Te as the heavy duty gear that actually takes me there. They all work together and source things differently towards something I value / wish to attain. The Fi is like a child saying "I want ice-cream!" and Te is the one that teaches the self how to drive and go to the ice cream store- equipping, learning, and engaging in the external structure required to gain what one desires. They do not feel like they are 'against each other' in that they work in opposite directions and in opposition to each other. Both are needed, and both form a complete set in my 'equipment'. I think people whose desires run contrary to what they do somehow have more deep-seated issues, be it denial, or repression, or whatever it is (in the mundane sense of the word). For example, the Fe wanting to give, but overgives without stopping to think and reflect (Ti) on the sensibility and logistics of things. There is a repression and/or denial of one's own, in this example, feelings, needs, and personal well-being, and the Ti is seen as the 'opposing force' that prevents the full extent of empathy the individual wants to give, say.
I never thought about it that way specifically before I read more about MBTI (those thoughts are very recent), but even before then, I've always thought that T-F were not 'opposing' forces, and a proficiency in one does not mean a weakness in the other, or that it works on a single linear scale where you have a ration of 100 skill points- '20 to Feeling, 80 to Thinking' and that you can't improve one without dampening the other. I don't have specific thoughts on the other functions, but I do suspect they work similarly.
I do agree in that it seems that it somehow seems to be common to see them as 'opposing forces' to each other, I do think they are tools in a toolbox and which ones you use depends on your preference (which is what MBTI is about), and a preference leads to usage, and extensive usage leads to skill, and doing so enough gives off a seeming big 'gap' that makes it look like it is one or the other.