What is the difference between language hierarchy and Grammar hierarchy for LL and LR?
A language is in a class if there exist a grammar of that class which generates the language.  Stating that for languages $LALR(1)=LR(1)$, means that when you have a $LR(1)$ grammar you can build a $LALR(1)$ grammar for the same language.  The grammar may be more complex than the $LR(1)$ grammar (for instance, it may use equivalent but different non-terminals to provide the finer distinction of contexts that $LR(1)$ gives for free).