How to fix Marksman without overpowering other AD champions

So, as we all know, Marksman just feels a bit off this season after the Armor Pen removal. With Lethality buffs we're seeing a standard 3 picks Varus, MF, and Jhin. So how can Marksman be fixed to allow more diversity while not drastically impacting other champions within the AD scaling spectrum. So my idea is why not add additional effects to common Marksman items that only activate on ranged AD auto attacks? I don't really have any ideas on effects that could work.