Here's where you're not making the right connection. That 10th level bard isn't really a 20-24th level AD&D character at all. If a prospective bard maxes fighter duration (7th level, 70,0001 XP), then maxes thief duration (8th level, +70,0001 XP), and then to bard (10th level, +110,000 XP), his...