First, it isn't clear that segregation is the right way to go. I am not convinced. The first thing that's going to happen is that an application scripted with the lisp-like language is going to want to import scripts written for an application scripted with the traditional algebraic language. Sure, sure, GUI, WIMP, and other gestural interfaces make a type-able syntax a bit less important than it used to be. In conclusion, let me ask a question.
C lacks first-class arrays.
C lacks a true two-dimensional or better namespace. Unix system calls are minimal and regular, but only hackers like them, and all the higher-level conventions to do with sockets and pseudoterminals and so on are incomprehensible to the casual user. And even hackers are abandoning Unix to pursue alternatives, because it's getting so old. If that's the rationale, Tcl strikes me as neither evil enough nor bud enough to be a good candidate for nipping. There are other jihads more fruitful to pursue than one against Tcl.