Well... What you may also consider is using Sailor ink. Inks like Kiwa-guro, Sei-Boku, Shigure, Doyou, Miruai, which I can vouch for, are quite lubricated. So lubricated that I have to use a nib size down to use them.
I prefer M European nibs typically with most inks, especially Noodler's, but I prefer Fine European nibs ( and sometimes EF is the nib is good enough) with these sailor inks I have.
The benefit of the Jentle inks in this context is that you can use finer nibs which use less ink, and they also write smaller, which I find more beneficial for EDC. European Medium nibs simply write too wide for me unless it's personal pleasure. But I will say, I love how Kiwa Guro in my Lamy Safari Medium nib still doesn't bleed through at all, even on Mead paper : )
Also Sailor inks are very well behaved, consistent, and good value for what you get...
... But the value has become a problem lately. The interesting Jentle inks that are more affordable have gone up in price... 50ml bottles are now being replaced with 20ml bottles, but sold at the same price if not more.
Just a heads up, some are still available on amazon right now for a descent price:
Otherwise you'd have to go to Andersonpens or Penchalet and pay a little more for some before they run out and your left with the overpriced 20ml bottles of these interesting colors if your interested in them...
Or if you check out Jetpens or vanness1938 you'll see the transition over to those smaller bottles with the same ink labeled as Sailor shikiori.
My other recommendation is a Lamy 2000 Fine nib, which is touted as a "best" workhorse and recommended by everyone practically, though pricey, it's a true workhorse and I love how it's a snap cap, and the nib sizes do run big.
I honestly think you'd like the Pilot Gold nibs. They start off smooth so going down to a Pilot M may not be as bad as you think regardless of the inks you choose. And if you can find inks like Sailor inks that make their Japanese Medium feel like a European Medium, it may be worth a sample at least. Of course I suggest researching how these inks work with those pens and also if they work well on the type of paper you'd be using them on, and also to see which fit your preference. You don't want an ink you don't like.