I too have a sandstorm team. Here is my advice:
Rock Slide/Stone Edge
Instead of having a mixed set, try to abuse Tyranitar's monstrous attack stat. Keep Stealth Rock since Tyranitar is your lead and Crunch since it a STAB move. Replace the other moves with Rock Slide (good chance to flinch)/Stone Edge (for good attack power) since it is a STAB move and Earthquake to cover its steel weakness. Give it leftovers instead of Life Orb so it can last longer in battle. Leftovers makes Tyranitar more of a tank while life orb makes Tyranitar more of a sweeper.
Kingdra in sandstorm won't survive very long. With Substitute also, Kingdra is worn down fast. It seems you need a pokemon that covers the team's rock, ground, and fire weaknesses. You might want to try Empoleon. He resists sandstorm and can take down fire, ground, and rock types pretty easily. Here is a set you might want to use.
252 Special Attack, 252 Health, 4 Defense
Surf is STAB move and can take down fire, rock, and ground types. Ice Beam takes donw grass types that Mamoswine and Tyranitar fear. Grass Knot is for Coverage against other water types. Yawn is a good status move with its 100% accuracy. Wise Glasses increases Empoleon's special attack by 10 %.
For Scizor, get rid of brick break and et U-Turn or Pursuit to benefit from its ability.
Gliscor is OK for a staller I guess. No need for any change here.
Mamoswine's moveset is OK too.
Instead of Psyshock for Alakazam, replace it with Psychic.
Hope I helped!
Lord of Reptiles