Well, I understand your feels dude. I've adjusted my play to better fit the situation at hand. Just looking at your example, you're playing wrong yourself already. Your team isn't near you to back you up, and you enter a 4v1 situation.
Granted, if they were there, it'd be easier for sure! But you can't rely on them, they're RNG. As a mediocre speed-runner for this game, I can confirm RNG can sometimes just screw you over.
However, in ranked matches, generally if you're good enough you could hold the center stage yourself. There are usually ~3 ways your enemy inklings can come at you from. Your goal is to use your ink to travel back and forth between them and just wall them out by killing them, or using bombs, etc. to generally be a jerk. As a wise man once said, "Winners are jerks."
In that situation, your best bet is to try and farm for a special and then come in with the back up of your special. Usually helps, and if you have like a killer wail, follow the killer wail path and kill anyone you pass by.
There are interesting movement things you can do, like shoot, squid, shoot to make it harder for your opponent and thus easier for you to win the battle. To try and practice fastest ways to areas and such, press 'Y' I believe on the match select screen and you can "Scout" the stages. So that helps!
My friend 'Koan', an A+ 99 player who's very inclined in finding tricks and sneaky things, is making a series. Right now it's for
Walleye Warehouse, but soon there will be more. He also streams on
Twitch.TV.
I know it seems like I'm just pushing him, and in a way I am. But only because he's put in a lot of work, and by watching and analyzing his thought process, I've improved a lot. Because now even I'm A+ 99! My aim was good, but the way I approached the game was completely wrong. And some tricky things he did helped me get that slight edge. So give him a shot.
I implore you to use weapons like Splattershot to get a good understanding of the game. If you main a roller it's fine, but it's kind've a gimmicky weapon and you'll end up losing to those who can play around it. (AKA Those who know the game.) I see a lot of people just try and cheese with Krak-On and stuff. Just... no. lol
Good situational awareness, ink coverage, and movement can not only escape/avoid Krak-On, you can also probably kill him when he pops into Inkling again.