You are really onto something here! Water is added to recipes for many different reasons. If you’re making a wine with flowers or dry fruits (like dandelion wine or elderberry wine) you’ll definitely need to add some liquid to simply have enough volume to ferment and for the flavors to be dissolved and distributed. However, using a lot of water in recipes of any kind risks a dilution of flavors, sugars, acids . . . everything! Making fruit and “country” wines can be tricky to dial in. You want the flavors, colors, and aromas of your primary material, but you also need enough sugar, acid, and sometimes tannin to get a balanced product at the end. I think your solution is simple: Grape concentrate needs to be part of your must and juice-adjustment arsenal.
Not only does grape concentrate (and you can buy all sorts of varieties to complement your other fruits and roots) contribute the aforementioned components, it also importantly provides yeast nutrition as well as mouthfeel and finish precursors to fermentations. Instead of adding just water and granulated sugar to recipes, try adding a solution of grape concentrate, adjusted to the correct initial Brix needed for your recipe, instead. Since it already contains acid, you may need to add fewer acid powders than are called for in the recipe or in the case of very high acid components you may even need to tweak the acidity down by adding potassium bicarbonate. Cabernet and elderberry is a classic combination, as are Chardonnay and dandelion — the sky’s the limit!
