Olimar: (6/4)
General Matchup:
Olimar's claim to fame is his ability to force his opponent to approach him by throwing the pikmin onto his opponent. This can quickly rack up a lot of damage if the pikmin go uncontested and can easily assist olimar into landing very early kills.
Olimar's most frequent kill move is the upsmash. Its his fastest smash as far as i know, is the strongest, and is the easiest to setup. It has a decent sized hitbox in front of him allowing for it to be used almost like a second forward smash. When at higher percents, purple pikmin can really hurt in the form of fairs/bairs and fsmashes. Also watch out for his back/up grab kills which, especially if blue pikmin are used, can hurt pretty early on.
Olimar's recovery is potentially one of the worst in the game, which isn't news to most people. GW's ability to gimp this recovery is readily available through the use of his quick disjointed tilts and aerials.
Because olimar is so bad off of the stage, you won't find olimars edgeguarding you too often. If they do try, go very low and you shouldn't have much trouble avoiding them.
Olimar's combo game mostly revolves around him landing grabs. A down throw can very easily set up to a dashing up smash (and then up airs and even an up b maybe) or another dash grab. Although mostly overlooked, falling nairs to uptilts and then up airs can also rack up a lot of damage too.
GW's combos on olimar don't look too different compared to most other characters. Olimar has super armor frames in the down b whistle attack, which could help him to power through some of your single hitting attacks and then make a quick counterattack. Down throw to dsmash works unless they tech per usual (olimar can't buffer a roll fast enough).
General Strategies:
The most imporant thing in this match to keep in mind is to always be nullifying his attempts to land sneak damage. If he gets distance, he'll probably start chucking pikmin, which you should always dtilt or nair away.
Try your best to keep olimar in the air. His best moves are done on the ground, so having him in the air takes away his best attributes. His aerials have low priority/range so you should be mostly uncontested.
The dtilt will go through all of olimar's approaches except for the grab. Even the fsmash is trounced by the mighty dtilt. Because olimar's aerials have poor range you will find yourself beating him almost all the time (olimar's up air will go through the key about half the time, keep this in mind).
Olimar players are very used to using the upward priority of their upsmash to ward off opponents approaching from above. The key will always go through the upsmash, and most of the time you can catch the olimar off guard.
Most of your kills will be landed through tech chases from the dsmash, random smashes you might be able to set up, but mostly through gimps. Learn to take away the olimar's double jump whenever they use it thought up b's/fairs/bairs/keys/dtilts. Once their jump is gone just hog the edge and get ready to tech/roll to the stage. Never go back onto the stage until you are absolutely sure he is dead, the up b reaches farther than you think.
If spaced correctly, the turtle can outreach the standing grab from olimar, however if they dash away and then back he will likely grab you. Try to avoid using fairs on their shield as the grab will usually punish you. Make good use of nairs and dodge to grabs from the air to approach. Any grab landed will likely end in a smash, and the nair will probably catch them and pop them up for further combo'ing.
I've heard rumors that the standing grab will reach below the stage, and has the potential to grab you out of your up b. If this does happen, then you will lose your stock as you are unable to up b after someone grabs you out of it. If this is true, the timing would be quite difficult I imagine, so just keep in mind although i don't think you will see it very often.
Stages:
Any stage with reduced amounts of ledges, or moving stages really hurt olimar a lot. Stages like rainbow cruise and frigate orpheon come to mind.
Avoid stages with excessive amounts of ledges, like norfair. This makes it almost impossible for you to edgehog them on a stage like this makes the battle quite a bit harder.