If I understand correctly, your system Fmax is now 200MHz, i.e. the slowest path in your system. (Your cordic probably has some paths that run much faster than 200MHz, but timing analysis is based on the slowest path, no matter how many paths there are.)
Also, if you're analyzing these two separately, don't just assume hooking them up will give the same results. Expect a little degradation as you fill up the device. (Or a lot, depending on how cautious you want to be, how much you plan on filling it up, and "how" your design fills up...)