This question was bound to come up at some point, it is a common challenge! So I am glad you have asked it.
It does tend to happen that many aerial parts are so light that it is hard to cover them with the alcohol/solvent at a 1:2 or 1:3 ratio. There are a couple of options here, and you covered some of them in your question. 🙂
1. Just leave it as it is and press down or shake/invert the jar every day. This makes sure all parts of the plant matter get some alcohol on them as often as possible, and that the plant matter isn’t exposed to air for very long. Once pressed this is still an effective medicine.
2. Keep measuring out more alcohol, and keep track of the ratio, until it covers the plant matter. You may end up with a 1:4, 1:5 or more, but this is still useful, you would adjust the dose accordingly when taking the herb.
3. Try grinding the plant matter, as you mentioned, however this still soaks up the alcohol pretty quickly and can be quite challenging to get as much of your menstruum out when you press it (unless you have a good tincture press and a fine filter).
I hope this gives an option that speaks to you,