Here are some other scenarios that could play out:
+ Jayden Nikorima plays well but can't get a bench gig because Barba plays there. He goes somewhere else and becomes a star.
+ Kodi Nikorima sees Barba and Boyd at the club and decides he has no chance. He goes somewhere else and becomes a star (I personally doubt it and don't rate him, but it's not impossible).
+ Ash Taylor plays well but can't get into first grade. He goes somewhere else and becomes a star.
+ A very good player becomes available. We find ourselves needing his services but are unable to buy him because we have both Barba and Boyd on the payroll.
+ One of our young players becomes a star. He gets big money offers and we find ourselves unable to compete because we have money tied up in both Barba and Boyd. The same could be true of one of our good players coming off contract.
+ WB feels obliged to play Barba from the bench, or thinks it is best. We end up finding ourselves a forward light in key games and lose due to our insistence on playing Barba in the 17 because he's Ben Barba.
So yes, whilst Boyd and Barba both have risks as individuals, the risk of having them both becomes increased. However, I don't think you really get much of a reward by having both Boyd and Barba both at the club. At the very best you have a high quality back up fullback, but with other options at the club it's a miniscule reward for what I perceive to be a massive risk.
And whilst I dislike Boyd, were it him already at our club and Barba the rumoured signing, I'd be equally against it. And if we have to sign Boyd, I'd much rather let Barba go than keep both. Keeping both is a big risk that offers no reward IMO.