The Russell 3000 fund most closely matches VTSMX (it presumably holds ~3000 stocks vs. ~3600 stocks in VTSMX). By combining the S&P 500 and Russell 2000 funds, you're essentially leaving out the 500 mid-cap stocks included in the Russell 3000 that sit between the top 500 and bottom 2000 (making things more complex for a lower benefit!)
Whether you allocation looks good is a separate question, since, as minimalist points out, bonds and international stocks are not part of either VTSMX or the 500/2000/3000 funds. But yes, it seems like a decent allocation to me. I might bump the bond allocation up a bit more, to 10-20% (anything lower than that doesn't really improve performance, and you may find that your risk tolerance isn't as high as you think it is), replace the 500/2000 with the 3000, and maybe even bump the international percentage a bit higher. But that's all nitpicking around the edges.