I reckon there's a lot to be learnt from both disciplines. At the weekend, the size of the kills told me I was out on my new ranges and that something was wrong. A few months ago I thought about bracketing ranges, just to see if it would be of benefit... it could have been. There's loads of other benefits as well to doing both, in their native format.
As for being good, yep, I reckon you can, really good? If your really good at one, with a few years of experience you could probably be good at both, but it would be dismissive of the skill of the top shooters to say you could just roll on into their domain without considerable effort. I'd reckon it would mean you'd be shooting an away comp every weekend, for perhaps 2 years to be top 10 in both...even if you were top 10 in the other first. A few years ago i'd say it would have been easier, but both formats have become competitive to a high degree to the extent where I reckon it would take a year (inc winter league) just to get you running... and you'd need to hit the ground running, have 2 rigs that were on the money, and a bit of luck to do it in both.
Saying that, the paper target shooters will shoot air and .22, but that's probably a little easier as you can shoot paper comps more easily during the week. However, after a couple of years i'm now finding that i need to work hard at 10m to progress, and time is becoming a factor... and I know FT will win that battle. (so we'll have to leave gold up to James Huckle i'm afraid...