You might want to work with one mutual fund family, if that family offers excellent funds in each asset class you want to hold. Staying with one family offers many advantages, such as free exchange privileges among funds and being able to see all of your holdings on one statement.
Those statements may include a graph, showing your current asset allocation, which will help with your planning. Suppose, for example, large-cap value funds have become overweighted in your portfolio. You could see the current allocation on the graph and take steps to re-balance your holdings.
You need to remember that “free” exchanges may be free of fees but not of taxes. Such exchanges, even within the same fund family, will trigger a taxable gain or loss.
