I would not dare say that relaunching STW or MTW with much improved RTW engine seems like running out of ideas.
Sengoku Jidai period had been seriously exploited by japanese producers like KOEI well before STW was released.
Same for medieval startegies.
My point is that it is inevitable for a game to be created that will cover Sengoku or medieval period in not too distant future. If we assume that, then it would bring CA no shame to do it properly themselves rather than making us play some botched clones made by other developers:-)
Hope those guys take my words into consideration.
I seriously would give my kidney to see STW and MTW re-released in, say, in 18 months with an engine that would make RTW seem obsolete.