Order of the monomials in y and z:

[y^4, y^3*z, y^2*z^2, y*z^3, z^4, y^3, y^2*z, y*z^2, z^3, y^2, y*z, z^2, y, z]

allLeadingTermsyz
{0: {0: 2*b5^3*b2^2,
  1: 2*b5^3*b34^2,
  2: 2*b5^3*b2^2,
  3: 2*b5^3*b34^2,
  4: 2*b5^3*b34^2 + 2*b5^3*b2^2,
  5: 2*b5^3*b34^2,
  6: 2*b5^3*b34^2 + 2*b5^3*b2^2,
  7: 2*b5^3*b2^2,
  8: 2*b5^3*b34^2 + 2*b5^3*b2^2},
 1: {0: -2*b5^3*b4^2,
  1: -2*b5^3*b4^2,
  2: -2*b5^3*b4^2,
  3: -2*b5^3*b4^2,
  4: -2*b5^3*b4^2,
  5: -2*b5^3*b4^2,
  6: -2*b5^3*b4^2,
  7: -2*b5^3*b4^2,
  8: -2*b5^3*b4^2},
 2: {0: 4*b5^5,
  1: 4*b5^5,
  2: 4*b5^5,
  3: 4*b5^5,
  4: 4*b5^5,
  5: 4*b5^5,
  6: 4*b5^5,
  7: 4*b5^5,
  8: 4*b5^5},
 3: {0: -4*b5^5,
  1: -4*b5^5,
  2: -4*b5^5,
  3: -4*b5^5,
  4: -4*b5^5,
  5: -4*b5^5,
  6: -4*b5^5,
  7: -4*b5^5,
  8: -4*b5^5},
 4: {0: b5^5,
  1: b5^5,
  2: b5^5,
  3: b5^5,
  4: b5^5,
  5: b5^5,
  6: b5^5,
  7: b5^5,
  8: b5^5},
 5: {0: -b5^4*b4^4*b2^2,
  1: -b5^4*b4^4*b34^2,
  2: b5^6*b2^4,
  3: b5^6*b34^4,
  4: -b5^4*b4^4*b34^2 - b5^4*b4^4*b2^2,
  5: -b5^4*b4^4*b34^2 + b5^6*b34^4,
  6: b5^6*b34^4 + 2*b5^6*b34^2*b2^2 + b5^6*b2^4,
  7: -b5^4*b4^4*b2^2 + b5^6*b2^4,
  8: -b5^4*b4^4*b34^2 + b5^6*b34^4 - b5^4*b4^4*b2^2 + 2*b5^6*b34^2*b2^2 + b5^6*b2^4},
 6: {0: 2*b5^6*b4^2*b2^2,
  1: -6*b5^6*b4^2*b34^2,
  2: 2*b5^6*b4^2*b2^2,
  3: -6*b5^6*b4^2*b34^2,
  4: -6*b5^6*b4^2*b34^2 + 2*b5^6*b4^2*b2^2,
  5: -6*b5^6*b4^2*b34^2,
  6: -6*b5^6*b4^2*b34^2 + 2*b5^6*b4^2*b2^2,
  7: 2*b5^6*b4^2*b2^2,
  8: -6*b5^6*b4^2*b34^2 + 2*b5^6*b4^2*b2^2},
 7: {0: -3*b5^6*b4^2*b2^2,
  1: 9*b5^6*b4^2*b34^2,
  2: -3*b5^6*b4^2*b2^2,
  3: 9*b5^6*b4^2*b34^2,
  4: 9*b5^6*b4^2*b34^2 - 3*b5^6*b4^2*b2^2,
  5: 9*b5^6*b4^2*b34^2,
  6: 9*b5^6*b4^2*b34^2 - 3*b5^6*b4^2*b2^2,
  7: -3*b5^6*b4^2*b2^2,
  8: 9*b5^6*b4^2*b34^2 - 3*b5^6*b4^2*b2^2},
 8: {0: b5^6*b4^2*b2^2,
  1: -3*b5^6*b4^2*b34^2,
  2: b5^6*b4^2*b2^2,
  3: -3*b5^6*b4^2*b34^2,
  4: -3*b5^6*b4^2*b34^2 + b5^6*b4^2*b2^2,
  5: -3*b5^6*b4^2*b34^2,
  6: -3*b5^6*b4^2*b34^2 + b5^6*b4^2*b2^2,
  7: b5^6*b4^2*b2^2,
  8: -3*b5^6*b4^2*b34^2 + b5^6*b4^2*b2^2},
 9: {0: -4*b5^7*b4^4*b34^2*b2^2,
  1: -4*b5^7*b4^4*b34^2*b2^2,
  2: -4*b5^7*b4^4*b34^2*b2^2,
  3: -4*b5^7*b4^4*b34^2*b2^2,
  4: -4*b5^7*b4^4*b34^2*b2^2,
  5: -4*b5^7*b4^4*b34^2*b2^2,
  6: -4*b5^7*b4^4*b34^2*b2^2,
  7: -4*b5^7*b4^4*b34^2*b2^2,
  8: -4*b5^7*b4^4*b34^2*b2^2},
 10: {0: 2*b5^7*b4^6*b34^2,
  1: 2*b5^7*b4^6*b34^2,
  2: 2*b5^7*b4^6*b34^2,
  3: 2*b5^7*b4^6*b34^2,
  4: 2*b5^7*b4^6*b34^2,
  5: 2*b5^7*b4^6*b34^2,
  6: 2*b5^7*b4^6*b34^2,
  7: 2*b5^7*b4^6*b34^2,
  8: 2*b5^7*b4^6*b34^2},
 11: {0: -b5^7*b4^6*b34^2,
  1: -b5^7*b4^6*b34^2,
  2: -b5^7*b4^6*b34^2,
  3: -b5^7*b4^6*b34^2,
  4: -b5^7*b4^6*b34^2,
  5: -b5^7*b4^6*b34^2,
  6: -b5^7*b4^6*b34^2,
  7: -b5^7*b4^6*b34^2,
  8: -b5^7*b4^6*b34^2},
 12: {0: b5^8*b4^8*b34^2*b2^2,
  1: b5^8*b4^8*b34^2*b2^2,
  2: b5^8*b4^8*b34^2*b2^2,
  3: b5^8*b4^8*b34^2*b2^2,
  4: b5^8*b4^8*b34^2*b2^2,
  5: b5^8*b4^8*b34^2*b2^2,
  6: b5^8*b4^8*b34^2*b2^2,
  7: b5^8*b4^8*b34^2*b2^2,
  8: b5^8*b4^8*b34^2*b2^2},
 13: {0: -b5^8*b4^8*b34^2*b2^2,
  1: -b5^8*b4^8*b34^2*b2^2,
  2: -b5^8*b4^8*b34^2*b2^2,
  3: -b5^8*b4^8*b34^2*b2^2,
  4: -b5^8*b4^8*b34^2*b2^2,
  5: -b5^8*b4^8*b34^2*b2^2,
  6: -b5^8*b4^8*b34^2*b2^2,
  7: -b5^8*b4^8*b34^2*b2^2,
  8: -b5^8*b4^8*b34^2*b2^2}}