YES

TRS:

  f(a()) -> f(b())
  g(b()) -> g(a())
  f(x) -> g(x)

max/plus interpretations on N:

  f_A(x1) = max{0, 2}
  f#_A(x1) = max{4, 2 + x1}
  a_A = 5
  a#_A = 5
  b_A = 1
  b#_A = 6
  g_A(x1) = max{1, 2}
  g#_A(x1) = max{0, 1}

precedence:

  f > b > g > a