Dumb example (reg: Te+Fi): you can be a leader of i.e. an office by good mannerisms and care for people. And that could come off as Fe, though the real master of you organizes like 35 people at once and knows about all their special needs, time tables and so on. Got my ENTJ boss in the back of the head, who is one hell of a boss.
I guess I can see that with my boss, although the introverted nature of INTJ tents to keep them from being massively engaged on a broad level like Fe.
ENTJ might have a better shot, it's just harder for them to get Fi developed to start with.
I don't think the functions are as clearly divided as they might seem in such a binary system, because no one is totally internalized or extraverted in nature. It's more a matter of priority. For Fi vs Fe, Fi tends to focus on the intrapersonal aspects of human value, while Fe tends to focus on the interpersonal aspects... but everyone cares to some degree about both (even T's -- it's just with T's, their higher priority is the impersonal assessment, where they don't instinctively trust their own value judgements and instead must dissect/analyze them just as they do outside data).
EDIT: I definitely saw a huge change in my boss when he suddenly started using Fi... he was such a machine before, controlling people like cogs... and suddenly he became superboss in terms of championing people. However, I still felt a very personal connection with him, he still was thinking in terms of people one-on-one rather than corporately... if that makes sense. So I identified it as Fi at work, he was viewing people as individuals and empowering them as individuals rather than approaching it from a top-down outside-in angle like Fe tends to do.
But I just don't know, maybe i'm reading too much into that, or just Forer-ing my own ideas. Hmmm....
In any case, yes, I think Tx+Fy can emulate Fx.