No. At a 20min 5k you're likely at genetic limit. Nothing will save you. The only way to improve now is to get your hands on a prototype alphafly with 3 carbon plates.
con-artist gimmick products destroyed the minimalist shoe industry before it could even take off. It's a shame, because regular thick running shoes are garbage and will grind your joints down until you are crippled.
There are regular minimalist shoes with no gimmicks, just a shoe with no cushioning. Problem is that's hard to sell for a high price. Merrill is the only really successful brand. Probably no more costly than Vibram though.
If people would just stop being so dumb, con-artists wouldn't always corner the market
Why are you interested in Vibram? Any experience running barefoot or in minimalist shoes?
I'd use the more normal zero drop shoes on the market and maybe just try the vibrams on grass at least until you can tell what its like to run in them.