Re: Need Help designing a Martial Duskblade
Sounds like a prestige class that combines the two, honestly. But if you are set on doing it as a base class, and aiming for tier 3, I'd make both progressions more limited, capping out at 4th level a la the Paladin/Ranger, and a slower maneuver progression than Warblade. (full initiator level, but fewer maneuvers known/readied)
Possibly make the maneuver refresh mechanic go based off spells (ie spend a spell slot to refresh your maneuvers. 0th level as a full action, 1st level as a standard, 2nd as a move, 3rd as a swift, 4th as a free), and make the ability to imbue spells into your strikes as a maneuver-esque ability.
If my text is blue, I'm being sarcastic. No, really. Don't bite my head off for saying the Fighter is way overpowered, or how Wizards need more spells per day to keep up.