YES

1 decompositions
 #1 -----------
   1: F(H(x1),x2) -> G(H(x1))
   2: H(I(x3)) -> I(x3)
   3: F(I(x4),x5) -> G(I(x4))

@Knuth and Bendix' criterion
--- R
   1: F(H(x1),x2) -> G(H(x1))
   2: H(I(x3)) -> I(x3)
   3: F(I(x4),x5) -> G(I(x4))

--- S
   1: F(H(x1),x2) -> G(H(x1))
   2: H(I(x3)) -> I(x3)
   3: F(I(x4),x5) -> G(I(x4))