A legume crop, or basically any non grass type crop ( as long as it is free of grass type  weeds or volunteers) preceding a wheat  crop would give excellent reduction of Takeall  in my world.   However, this is a "one crop per year" environment, and I can't suggest a  likely success rate  for any other.   Other than to say that a wet summer was  alwasy considerd to reduce takeall by allowing the fungus and infected  wheat crowns to breakdown, rather than sit hibernating in dry soil.  (  You need to understand that winter is my growing season, and summer is when everything is usually dormant )     My understanding is that that reduction from growing a  non host is due to denying the fungus  somewhere to live and propogate, and therefore basically starving the fungus, rather than any magical "fungus killing ability".   In a situation where there  was a massive amount of inoculum, and especially if the season was very dry, then there still may be enough carryover even after the starving session, to cause problems in the following season.

Oats have always been considered a  takeall cleaner here, but i understand there is a variety of Takeall that will affect oats  in some places of the world..  

Also, according to this link, some varieties of Triticale have useful resistance, but what varieties..?   http://www.hgca.com/hgca/wde/diseases/Take%20all/Tacont.html  

Can you be more specific about your concerns and confusion  ?

What is wrong with  growing your legume cover crop, and then using Flutriafol fungicide in the following wheat to be sure.? The fungicide is not an expensive exercise comparitively.