As a Mika Main, the worst thing you can do is Jump in.
Guiles will Flash kick, any and all Jump ins you even attempt.
Dashing after a neutral jump, charged HK, and HP shooting peach to punish booms is the way to get in. Jumping in is just a way to get countered every time. Most guiles try and jab you out at close range, or grab so you can do a little shimmy or spacing and keep command grabbing their counters.
To me, playing guiles are predictable. Only of few of them are ever very offensive, when they start to turtle, it gives me time to develop a strategy.
I dunno if I agree with this at all. HP Shooting Peach is an extremely risky tool to get in, and you're not going to be able to call out different boom speeds by using that, unlike other universal fireball counter moves other characters have.
Charged HK is mainly a no-go in this MU. I play Guile, and it's so extremely easy to punish that anytime I see the Mika going for it when I'm against one.
Dashing, in general, is inadvisable because you'll either eat a sobat to the face or a boom. Guile has superior footsie tools, projectile pokes and all that jazz.
I really think it comes down to a very slow, methodical approach of walking, blocking, walking, blocking. With the projectiles being any Guile's go-to, they'll usually hesitate doing anything when you're in proper jump-in range, since they're holding down-back for something. So they'll try to use misdirection by pressing buttons like throw whiffs or cr.MKs to cover up whether they're gonna fireball or if they're looking to counter the jump-in. During that time, you
can try the charged drop kick if you guess right and they were hesitating to throw a fireball, or they just lost their charge. Otherwise, it's about recognizing the very moment they want to throw an FB, and jumping in.
You can't win in a footsie game against Guile, so you eventually have to do something dramatic. Maybe baiting a somersault with a dive bomb. Maybe sliding under a slow fireball as they follow it in and getting in that way. Maybe getting a good length away from a (meterless) Guile and talking into the mic. Stuff like that.
But from my experience, those reckless ways of getting in is what I'm looking for as Guile because I'll just quickly kill a Mika, seeing them get more and more impatient, and making my job easier. When their guard is really up and I throw one bad fireball, and then they get the jump-in... that's when it gets bad for me.