Dual Wielding Rune Knight

Hi, I'm playing a fighter in a campaign intended for level 10-11, we're approaching level 4. I'm curious to know what's the best route to take forward - game is somewhat deadly and unforgiving. My PC details:

• Rune Knight DEX Fighter
• Dual Wielding with Shortsword and Scimitar
• Stats currently are 8, 17, 16, 8, 14, 10.
• Human with Magic Initiate (Shield) and Alert

The issue that I'm looking to address is the lack of damage riders on the multiple attacks, and the fact that progression on Rune Knight isnt that great outside of the increased number of runes (2 at 3, 3 at 7, 4 at 10). Giant's might esp. has been nerfed with changes to grapple, and 10th level feature is a joke. I currently am debating between three main routes in mind.

 

1. Straight Fighter

• Dual Wielder at lvl 4 (DEX 18), Mage Slayer at lvl 6 (DEX 19), Defensive Duelist at lvl 8 (DEX 20)

 

2. Ranger Dip Earliest I'd take this is at level 6. Mainly to get hunter's mark, since there arent any other riders for the multiple attacks i make. It'd slow the progression, and Fighter from 5-8 is banger after banger. The spells would also open up some extra casting of shield if necessary.

Pros

• Two more spell slots (for shield or others)
• Additional skill Proficiency
• Access to free Hunter's Mark. Pairs well with the multiple attacks.
• Access to Absorb elements, or additional spell

Cons

• Might not reach Fighter 10 for 4th rune, or 11 for double extra attacks
• Bonus Action clog - Giant's Might, Hunter's Mark, some Runes
• Delayed ASI + Runes progression

 

3. Monk Dip Earliest I'd take this is at Level 5, making it a pseudo extra attack. Main thing here is the essentially free Dual Wielder, opening up the an ASI for other goodies. And with Monks Defense, could get AC upto 17 by level 8.

Pros

• Better AC from unarmored defense
• Free weaponized bonus action, opening up another feat option
• Option to grapple, since it uses DEX as modifier

Cons

• Might not reach Fighter 10 for 4th rune, or 11 for double extra attacks
• Delayed ASI + Runes progression

 

With all this in mind, would like to know your thoughts on the following

1. Is multiclassing worth it? Key trade off being the extra damage vs more runes.
2. If multiclassing, which is the better route, and is there a specific breakpoint to pick up a dip? I'm curious to know if there is any way to number crunch keeping attacks, BAs, casting etc in mind.

Thank You.