Yeah, guides are very useful but ultimately there's only so much they can do for someone who's under-leveled or whatever. On the bright side if you stick with the game long enough you should eventually hit a turning point where event units and gachas allow you to start from a Common Unit/Low Rarity guide and simplify from there rather than struggle to keep up on most maps. For example, my own team has enough single target damage capability that I can often look at a video mostly to identify the early rushes and then simply brute force my way through things that would require tank swaps and a ton of skill activation if i were using silver units.