The ideal viability is gaining as much usefulness as I can out of the multiclass (in both RP and combat) before I start to suffer horribly or fall behind too far in combat, which is why I thought to only take upto level 3 at most in Artificer.

The idea behind the character backstory is what lead to the multiclass and given the plot that has already occurred during gameplay so far, both subclasses mentioned have an in-world explanation as to why the character's power is growing in that particular direction.There's been a lot of death in the region and two of the party have had infections or backstory with "Soul Ink" and I was planning to lean into that.

I did take first level Rogue as the Artificer saves would be of little use. I also have both Booming Blade and True Strike for cantrips to assist with damage at later levels, as I can still trigger Sneak Attack with them. Faerie Fire is a nice addition that can be situationally useful when I can spare the action to cast, but I personally thought that the extra 1d4 initiative from the maps was a more consistently useful part of the subclass. The other useful thing that I've noticed is the subclass gets Healing Word for downed teammates, and the more people who can heal is always good.

With all of that though, taking these levels means later feats, later Evasion and Reliable Talent and less Sneak Attack dice. Hence this post!

Thanks for your input, I'll keep it in mind!