The combined total is only a few more hits than Pete Rose's record, so why wouldn't it be possible? That said, he needs 400 or so more hits. Ichiro is 39 years old and is currently hitting .200, so I wouldn't place my bets just yet.
I thought like Wilt Chamberlin's 100 points in a basketball game, getting 4,000 pro hits in baseball is just something that happens once in the universe. Ichiro is way to old to reach 4,000 but with his late start in US pro league stuff, he will hit 3,000 but probably limp there and get in unnoticed since he split his career in two countries. Looking at the new high percentage hitters today, and there are a lot of those moneyball types, nobody among that crew could even string two seasons with a 200+ hit season.
Ichiro is one of the great hitters but had he hit 3,000 with all 200+ hit seasons, let's say in just over 13 seasons, then people would be calling him the greatest of all time. But with fielding, a World Series win, and home run capability, the greatest for average player is Willie Mays and that will never be achieved. Ichiro would have to get ring or at least WS and postseason production like a Bonds, retire at 3,500 hits, and look like a kid into well into his 40s to be considered among Cobb, Mays, and Ruth.
At least for my generation of players I have watched since Mays, Ichiro is the best to ever have picked up a bat.
As for pitching, the most wicked rotation were the '90s Atlanta Braves and I doubt I will ever see that type of three Cy Young pitcher teams in my life. If Cain lives up to salary and gets that Cy Young people say he has the capability of doing, and Zito (2012-13 16 win streak, also a part of A's great streak many years ago and Cy Young winner) and Lincecum (back to back Cy Youngs, 2010 reliable postseason ace, one-two punch with Zito to take out Verlander and Tigers in 2012 WS game 1) help the team achieve a third WS victory or NL pennant, then I would put them in the same viciousness category as the 1990's Atlanta Braves. With so many great players getting traded off to highest bidder, it's just not possible to get a Glavine, Smoltz, and Maddux pitching a team into such crazy numbers. With rich teams like the Yankees, it pretty much rules out another 90's Atlanta rotation.
In football, California Bay Area product Tom Brady can play into early 40s too (crossing fingers for staying healthy) and if the planets line up right, will get either record 6th Super Bowl appearance, or even 4th and 5th Super Bowl rings which would put him in a similarly untouchable position for the record books.
And out here in California way back when, we already witnessed the greatest streak and domination in all of sports which was Coach Wooden's long run with the amazing UCLA basketball team. What made it even more unbelievable was that he didn't have the benefit of long runs with any single top player and had to reinvent the team every year when seniors graduated or were drafted.