I haven't posted in a while...so what the hell, eh?
Listen to those before me. There isn't a shovel big enough to move that load. They are definitely not mutually exclusive principles.
Watch a boxing match and you'll be able to see better evasiveness than most, if not all Aikidoka. Slipping, bobbing, weaving and footwork are all integral parts of boxing's defense as well as parrying, blocking, etc.
I think it's fair to say that most if not all high level practioners of grappling arts welcome force they can use against their opponenet. Judo has its notorious "kuzushi" meaning unbalancing techniques, which are often used to get an opponent to push back at you so you can use their force and help them along to the ground rather than using strength alone.
Watch any Muay Thai or MMA match and witness grappling standing (clinch) fighting with strikes. MMA matches also allow for ground and pound as well as striking from many different guard varients and sometimes inferior posistions. Some fighters (Bas Rutten comes to mind) are/were devastating strikers from their backs. Although not all elements of boxing defense can be seen in Muay Thai and MMA, many elements are still retained. Because MMA includes grappling, many skilled MMA fighters use previously mentioned grappling tactics associated with an "Aikido mentality".