Personally I think the wand system works out ok as it is. With Palmer, I had an easy shield source and a moderately easy aura source and a royal pain in the ass barrier source. I didn't find my barrier source until well after hero, but I had the other two earlier. While my shield and aura sources were relatively easy, both had some major drawbacks that may not appear obvious unless you play the same character with the same sources for an extended period of time in that you are continually going back to the same places over and over again. This means that if your enemies are good at following you, they can set up ambushes in that spot and generally catch you. Granted this is true for any pattern, but with wands there isn't really a workaround.

Example: I used the old dwarf as a regular source of zombies, so anyone could wait and ambush me when I was going to kill him and more than one ranger did exactly that. However, I could summon the mob sometimes, so that might not be the best solution to finding me. But, if I always have to go to X spot to get the wands, you can find me there almost every login at some point. This didn't really ever happen with Palmer that I recall, but since I was extremely cognizant of it, I made sure I used different routes and did whatever I could to disguise what I was really doing.

Back to your general question though, I don't think having abs readily available to me made that big a difference, but that could also be my playstyle at work. I got my first kill with Palmer at level 11 and for the most part got at least one kill every level thereafter, so for the bulk of my kills I had no preps. Once I hit hero I sort of felt I needed the preps, but with a few exceptions I really didn't need them. They helped me with killing mobs more than anything and perhaps they made me more confident that I could walk into a situation and not die so quickly that I couldn't get out, so I was more likely to mix it up, but it was a very rare fight that came out that close. Most of my fights were fairly one-sided in that I either was going to get a kill or the person was going to get away (or I was going to die, but I don't dwell on that) and those various preps really didn't make much of a difference except perhaps from a psychological point of view.

Ymmv, but I really don't think that abs makes that big a difference and I think the system we have works fairly well.