That's no different from live action - I can put on any old movie and go "Oh there's Stallone" or "there's Jackie Chan"
I actually find it quite comfortable. A few different voices now and then are nice, but having entirely new casts is just uncomfortable
I agree with you up to a certain point; I agree that it is comforting to hear familiar VA's doing many of these animes, but I disagree with your Stallone/Chan comparision - actors like that are not in every second or third movie that a particular studio puts out. So in other words, Universal or New Line Cinema don't use actors like Ewan Macgregor or Christian Bale on most of their productions.
However, I will admit, most anime studios or production/marketing companies use a lot of the same actors, Funimation, Sentai/Section 23, Viz always use Ocean it seems.
Also, I find Funimation are the butt of most of the "get more actors" jokes when they have a considerable amont of actors, but I must admit, I do laugh at some of those jokes though.
There is one issue I have come up with about English dubs though, it came to me when I was streaming the new Haganai episodes - the Japanese voices seem to have a little more of a rustic sound to them - basically there is some purposeful vocal cracks, or how the little kids get a bit of a growl and there's a vulgar sound to some of the characters - this adds to the effect of the series and the humor.
I find sometimes(not always) with Funimation, the actors sound too good, too clean and polished. For example, Monica Rial is an amazing VA who does a lot of young girl voices, but a lot of the time when she soes these voices she sounds too clean, it would be nice if they'd experiement a little and get her to throw some dirt on the voice every now and then.
This is why I give props to Brittney Karbowski especially when she plays teenage girl characters - she is somehow able to get that authentic prepubescent crack that girls like that get when they are worked up or excited. Basically, she's putting some dirt on the voice, a perfect example is the way she executed the lead role for B Gata H Kei.
Don't get me wrong though, I'm big on dubs, all I'm offering here is a little criticism.