Rather than start another tier, create multiple Tour Legend Golf Tours just like the pros in real life. The equivalent of the PGA Tour gets worthwhile large payouts and reduce the prizes by tour drastically. Over the course of the season promote and demote people among tours like the pros do now. Place above a certain level each season to retain your "card". Win three on a lesser tour and move up. Top 25 at the end of a season earn their promotion to the next tour.
Heavily promote and feature the very top tour of elite players. That's where the cream of the crop will be.
Something similar could be done at the Legend tier as the means for Tour Legend achievement. Promotion to the Tour Legend level would then have to be earned across many courses and conditions over an entire season and not automatic.
Demote the bottom players of the Tour Legend group back to Legend if they're not up to the task of retaining their "card" on the lowest tour in the TL tier.
Badge the player similar to the WGT flags we have now so each member is readily identified by the tour he/she is currently on.