It actually does matter. Atum heals for 2k (or higher, JP wiki says 3k, which is higher than I remember but I haven't tested her recently) but actually only heals 20% hp, so you can't even make full use of her heal unless your hp is at least 10k. Adding ascension actually further raises that break point. Sol technically has that problem, too, but not as extreme (33% heal capped at 1.8k) - you won't run into it once you hit around 8-9k-ish hp depending what size ascension you use.
Checked it against JP wiki, it looks fine to me: Pride (++) at SL20 is 10% base assault + 20% pride multiplier; assault at SL20 is 10% base assault with no pride multiplier, so it becomes 10%+10% / 20%+0% = 20%/20%.
It depends on your playstyle. If you like to eat OD to build burst, the pride effect gets amplified by your burst multiplier and can add up to a lot of dmg. It's also relevant to himes like Kali that revolves around living life on the edge. Just ignore it if neither of those applies to you.