Lets see
Sandslash
Good set but it needs a little improvement.This set is greater to use in RU.
Sandslash@Leftovers
Trait:Sand rush
Impish nature(+DeF,-SpA)
EV'S 252 Hp/252 Def/4 SpD
Sandstorm
Earthquake
Stone edge
Stealth rock
With access to Stealth Rock , Sandslash is primed for a support
role, and can work particularly well as a lead. The EVs here optimize
physical defense, allowing Sandslash to check or counter some of the
premier physical attackers in the tier, such as Aggron, Aerodactyl,
and Electivire, and to effectively wall and set up against weaker
physical attackers. Earthquake is a reliable and strong STAB move that
prevents it from becoming Taunt bait, whilst Stone Edge allows it to
deal damage to those immune or resistant to its STAB move.SAnstorm to
raise your spped because of the ability sand rush
.
Magmortor
Take out overheat.You lose a tonne of SpA using that move.Let us go to a more reliable move.Enter our good friend flamethrower.Good move.good power and also has a chance to burn(10%).Other moves are good.No changes to that.
Whimsicott
It needs some improvement.I shall give you a moveset.
Whimsicott@Leftovers
Trait:Prankster
Nature bold(+DeF,-AtK)
EV'S 252 Hp/252 Def/4 Spd
Stun spore
Mememto
Encore
Giga drain
This is Whimsicott's best set, and can be manipulated to fit onto a
wide variety of teams. Prioritized Stun Spore is extremely annoying
for the opponent, especially when it can paralyze Ground-type Pokemon
that are normally immune to Thunder Wave—this can greatly aid a slower
sweeper, such as Nidoqueen, and give it the opportunity to sweep. If
you would like to bring in a teammate that is a setup sweeper, then
Memento may be more appealing, as it will most likely force the
opponent to switch out, giving your sweeper a free turn to set up.
Encore is another reliable way to force switches and aid setup
sweepers, as forcing your opponent to continually use a move such as
Protect will provide a massive setup opportunity for a teammate.Giga
Drain is Whimsicott's best weapon against the likes of Rhydon,
Omastar, Kabutops, Feraligatr, and other Water- and Rock-types;
All from smogan.
Munchlax
It looks pretty good.So no changes to it.
Tangrowth
I love your tangrowth's moveset.It is pretty good.Another choice is to go with ancient power.It is more reliable and has a chance of raising all your stats.If you think your Hp is good, then stick to it.Other than that its great.
Bouffalant
Good moveset and looks more offensive.So nothing to it.