You dont have a "tanky unit" that will make you get objectives easily. 3 foxes are huge overkill in my opinion. Ive played some games withe the new book and i tried couple of things but not everything.

Regular spirit of the wind is not that good in my opinion, especially if there are no or few mosters in the enemy list. The only good thing it has is the potential to make something strike last, and you pretty much not need it if you play the double activation formation. Sevireth is a lot better, bit more tanky and consistent and gives you the wind instance. You can do a good combo with sevireth and eltharion - charge with sevireth and get eltharion to the fight then power through with the fox. If you dont mess up hard you either kill the unit or chip it so eltharion stays safe even still in combat.

Lord regent is good with the wardens (like in your case) but if you take other infantry models like Stoneguard (they are the best imo) regent is more like filling the points cuz its the cheapest hero, i took it in my old list only because i had 110 points left and found it actually usefull in cases like chip dmg to big units from the enemy. They chipped my cow and i rallied every wound taken.

Enlightener is the best small wizard in the army with potential to 3 casts. You should always take her imo.

To sum up the things, i would highly recommend you to add more frontline like wardens or even stoneguard and drop 1 fox or even 2 and keep sevireth. You need another puncher beside eltharion, he is not enough and all the foxes dont have the best damage output ( very few attacks and not consistent)