--35% Total Stock (VTSMX)
--18% Total International Stock (VTIAX)
--5% FTSE All-World ex-US Small-Cap (VFSVX)
Of your stock holdings:
--35/58 = 60% domestic
--23/58 = 40% international
It is my personal opinion that the big principles are "Time is your friend, impulse is your enemy," "Stay the course," and "The majesty of simplicity." Let me add my version of the first two: my wife's dad used to say, in a different context, "Don't fiddle, don't diddle."
So the question is: is there anything about this portfolio that means you need to do something?
1) You say "Ideally I want to hold about 45% in bonds." In my opinion, 42% *IS* "about 45% in bonds." So, no need to do anything there.
2) Your stocks are 40% international. Vanguard says "Although there is no right answer for all investors, empirical and practical considerations suggest a reasonable starting allocation to non-U.S. stocks of 20%, with an upper limit based on global market capitalization." Vanguard itself allocates about 30% in its all-in-one funds. In my opinion, 40% is close to 30%, and 40% is also close to "global market capitalization" (currently 50-55%). It is my personal opinion that 40% is indeed a "middle-of-the-road" allocation. (My own allocation is 20%; I'd call it "well within the beaten path, but not in the middle of the road.")
3) You want your portfolio to be simple. My personal opinion is that it IS simple.
4) OK, what you've done with small-caps is inconsistent and a little irrational, but it's only 5% and I would just... leave it alone on the grand principles of "Time is your friend, impulse is your enemy," "stay the course," and "don't fiddle, don't diddle." The reason why it's inconsistent is this. The great divide in this forum is between "total market" investors and those who "tilt." "Total market" means trying to match the whole market by capitalization weight. In your domestic stocks, you are doing this, but in your international stocks, you have a small-cap tilt.
My personal guess is that you set up this portfolio in 2009 or 2010. By jove, Sherlock, how do you deduce these things? You know my methods, Watson: apply them. VFSVX was launched in 4/2/2009. At that time, VGTSX was a patchwork quilt of old indices, and was missing small-caps (and Canada). In that time frame, a purist might well have wanted VFSVX to repair the omission of small-caps. On 9/24/2010 Vanguard announced that VGTSX would now track the MSCI ACWI ex-US IMI which is a total market index including mid-caps and small-caps (and Canada). Oh, Holmes, I thought for a moment you had done something clever, but now I see it is absurdly simple.
Since the total market includes large-caps, mid-caps, and small-caps, a total market fund will include large-caps, mid-caps, and small-caps. Since large-caps in fact represent the bulk of the market, total market funds will be dominated by large-caps anyway. In Ye Old Days... prior to the discovery of the (disputed) "small-company effect" in 1980, nobody cared and the S&P 500 was thought of as essentially the total market.
Total market purists now want the true total market, and since Total Stock's expense ratio is only 0.01% higher than 500 Index, I don't think there are any low-cost purists who recommend 500 Index any more.
"Tilters" give a variety of reasons for departing from the total market portfolio. (I put it in the same category as acupuncture: there might well be something to it, yes seriously--but I don't personally tilt and I don't personally use acupuncture). The commonest tilt is to add extra small-caps, which you've done in international.
Anyway, you have a small-cap tilt in your international but not in your domestic. Well, let me add another grand principle to the others I've enumerated. "A foolish consistency is the hobgoblin of little minds."--Emerson.
Annual income twenty pounds, annual expenditure nineteen nineteen and six, result happiness; Annual income twenty pounds, annual expenditure twenty pounds ought and six, result misery.