This is a big Java problem with Guava and logging libraries that get included with everything. If you bundle together enough projects you are bound to have an satisfiable breaking mismatch. The hip trend is "just use the latest from maven"so hipsters have a canned reply, "OMG!!! YOUR VERSIONS IS SOO OLD" , but in the real world we have to support environments outside our laptop and we cant always be updating things every day for no real reason, angry administrators say "WHY DOES YOUR GUAVA NEED TO BE UPGRADED? IS THERE A BUG?" :)
So yes, while I do think Guava is a nice library, the breaking changes in it are PITA, and the things inside it generally are things you can do yourself. Preconditions.checkNotNull(Object) for example seems sexy but over time you always hit an issue like this since guava gets included everywhere. As a result I commonly end up stripping out guava in out projects.
::Rant over::Your only hope is to build a fork of one hector or astynax that uses the same guava version or get both the projects to update to the same version.