Even I'm playing this now (for the first time) and I just started Chapter 4. There's no specific strategy that I could think of, except for relying on parrying in the best way possible.
Also, using Atreus' arrows helps a lot, too. Combines effortlessly as a mid-point during Kratos' Light + Heavy combos.
For groups, check if you have equipped some rune attacks which allow you to do some area attacks. There's one that stuns multiple of them. However, I must add, that timing them right would be crucial for it to be effective.
BTW, what difficulty are you playing on? I'm playing on Normal and overall, it's just the right amount of challenge. Nothing too difficult or frustrating.
About the game, it's sooooo much better in terms of how the narrative is paced, compared to previous GoW games. I have never liked any of the previous games (tried playing multiple times over several years but just can't play post 2-3 hours of the first game).
It borrows heavily from UC4 and TLoU (not complaining at all) and it's very evident.
Also, the combat is 😍. The weight of the character, the animations and the movements really are something else. A lot of care has gone in the game and it's evident with every passing moment.
The side-quests are simply, kinda meh. Totally unnecessary, IMO. Barely adds anything to the overall game. Seems kinda tacked-on.
The main story however, is very intriguing and there's an instant connect I felt with the characters. This wasn't the case with the old GoW games. In those games, Kratos is just mindlessly killing and killing with no end in sight (at least the game doesn't make it clear). Here, I love the calm and composed Kratos who has a sense of responsibility.
Overall, loving the game and looking forward to the story.