I became so confused ; if your app did not related with greater than about 10 or some more or less , why U choosed so complicated patterns ?! my main idea is not about minus or plus ur entities count ,but it is about change ur design pattern .

With respect to other friends and their answers , I think u choose hardest way to solve this problem in the world in all time . changing bytecode after it generate , cause so many future problem if U don't work on tiny app . I'm not very professional in this way but , by this reason I always took simplest way . I realize this problem in MVC design pattern , if U drop UR entities in Model project , not only is not a problem but also is a regular way to create DBMS apps . so I don't know which IDE u use to ceate this app , but i can suggest to U if U
use Oracle DB or any DB with JDBC:ODBC Bridge connection , try oracle JDeveloper .
It's very fast,Helpful and reliable spc with MVC and EJB3 .

if it's not helpful sorry to waste your time . I just wanna help you