YES

1 decompositions
 #1 -----------
   1: H(H(x1)) -> K(x1)
   2: H(K(x2)) -> K(H(x2))

@Knuth and Bendix' criterion
--- R
   1: H(H(x1)) -> K(x1)
   2: H(K(x2)) -> K(H(x2))

--- S
   1: H(H(x1)) -> K(x1)
   2: H(K(x2)) -> K(H(x2))