From what I've seen with HR teams in OL's is this...
I truly think it's easier to make the playoffs with a HR team but much more difficult to win the WS. As long as you have a good pitching staff in an OL you have a very good chance to make the playoffs. With pitching being so darn cheap right now you don't even need to look very hard to put together a dynamite staff. Just do a simple ERC# and HR/9+ search and you're golden. Unfortunately, many owners don't read these forums so HR teams in OL can do great.
Once you make the playoffs, it's a whole different ballgame. If you run into a team who's pitchers don't give up many HR you will have a very difficult time.
HR are expensive. If you want high AVG and high HR you will pay alot for those type of guys as theyre the most expensive in the sim. If all it takes is 2-3 SP who gave up 3 HR in 350 IP to turn your HR team into a complete waste I'd think long and hard (that's what she said) about it.
I think the best way to do it atm is find a few guys who have good normalized HR#, maybe around 3-5# with good AVG (.300+) and OBP (.380+). There's some good cheap guys who will give you more production against different types of pitchers and parks.