It's a very vague question. I think the answer is "Yes." (and i'm an acknowledge Davis skeptic). But I think there are some caveats.
1. Money. A starter at what percentage of the salary cap? Certainly not at the average salary for starting power forwards. He's a below average starter. At a discount relative to other starters, there's a chance.
2. Yes, he can start. But more in a way of "our building blocks are Rondo, Player X and Player Y, and we fill in with Perk and Davis" but definitely not a "our foundation is Rondo, Perk, and Davis and we'll fill in with Player Z and Player W" kind of mentality.
3. Yes, he can technically be a starter on a contender. In the way that: a slipped Bruce Bowen, a slipped Stackhouse, udonis haslem, antoine walker, drew gooden, larry hughes, matt bonner, derek fisher, pietrus, Aaron Mckie, Tyrone Hill, etc. all started for teams ending up in or near the championship game. Basically, yeah, he can start by doing one or two things very well and being the 4th or 5th best starter surrounded by a Big Three type including a duncan, kobe, prime iverson, wade, lebron, etc. type of player (or less elite but true big three type of team).