I think the reason for water in recipes is because they want you to bring it up to a certain amount of gallons, like a 5 gallon carboy, so that your measures of nutrient, pectice enzyme,etc. are easy to figure. If they didn't do that, they wouldn't even need to sell recipe books because all the chemistry measures would depend on how much fruit you use so they couldn't even guide you.
Recipes make something that's drinkable without having a good understanding of what the chemistries DO. Anyone--even a kid--could do it.
Recipes are a good way to cut your teeth on winemaking. But once you understand what you're doing, it's very wise to go"off-recipe."
Water additions to control PH is not the way to go. If your TA is too low after PH adjustment, then water can be used to get it back up. That would only happen if you had to add acid. But you can also go the route,with fruit, of not really measuring TA and just go with PH because taste is everything on fruit wines, IMO. If a big fruit wine is too acid, it's not pleasant to drink and you have to add too much sugar, then, to balance out all the acid. That's why PH adjustment is so important.
Always start out measuring PH of the must. Get it correctly adjusted at the primary before you set your brix,pitch yeast,etc. The result will be a problem-free wine. Buy a PH meter if you don't have one. If the acid is too much, use calcium carbonate to get the PH up. And another tip--on the first day, get some pectic enzyme on the must--you get more accurate PH measures, on the second day, once you have some of the fruit broken down.
Oh, I don't think a fruit wine can be too fruity--that's what it's supposed to taste like. I hate a fruit wine that has that "wine" flavor to it--it means there is too much water dilution. We make a LOT of fruit wine. Each one tastes like the fruit it's made from.
The main problem with going off recipe is that you have to estimate how many gallons the fruit will make and adjust the amount of your chemistries according to that. It confuses you in the beginning, but when you do it a couple times, it's more understandable. Need more help when actually going to do it?---let us know because many people on this forum seem to be doing the same thing we are.