Here is my 2 cents.
Use the spot dodge, You can spotdodge his grab, and grab him first. Which leads to down-throw + combos
I use it possibly more than shield depending if the marth loves Grabs or f-airs.
Learn to wavedash out of shield. Works really good on marth's Forward smash. If you shield it you can wavedash out of it fast and grab marth before he can really do anything.
IF marth throws you up at low% don't DI and Neutral Air, If he gets a tipper'd up-tilt on you your gonna get combo'd.
Anytime you get a jab off probably like 70% of the time, you want to just run in and grab after it. Crouch cancel his aerials at low percents, especially if he's mid-high percent. Unless he goes for l-canceled down-air not sure how long the stun is, but it's pretty long on ur crounch cancel. Not sure you can always follow up.
What they mean by stay in close is keep marth defensive. Unleash a hell of l-cancels jabs, and grabs depending on the situation. When I'm marth and shieks get in real close, My first thought normally is to shield the dash attack, seeing as how marth's background dodge is laggy enough that if shiek mises her grab, she's sometimes safe anyways. If you do miss a grab, hold L, and down on C-stick so after the grab is done, you background dodge on the quickest frame you can start it.
IF your not in close, charge needles and throw them to make him come to you. The object of this is so you can bait him to come after you so you can either Crouch cancel - Downtilt, Shieldgrab, or dashdance-wavedash just out of range right after his first swing of his double f-air, charge in with a dash attack, or w/e.
Just be weary of upthrow tilts- f-air combos.
your edge game should be almost good enough to ATLEAST make a marth think twice about going near it.
