The best way to approach this divide between magic and physical talents is to balance them, like you would balance them in a video game. Because you, yourself, are defining what magicians can do, and what physical artists can do, you can balance them.
One common thread in many of these answers is that magic offers a way to hold onto great potential energy and then unleash it all at once. Thus, as long as a magician can have time to charge, they're invincible. We're going to have to tailor that if we want to balance these awesome powers.
I would recommend having mages harness their energy in a form that is closely tied to the spell that you intend to cast. An extreme version of this might be the Dungeons and Dragons approach of your wizard having to memorize a set of spells every morning, and they can only cast the spells they memorized (consuming one charge of Fireball for every Fireball cast). If desired, you might give them the ability to change one energy into another over time (letting them memorize a Fireball, and with 10 minutes of concentration turn it into a Healing spell). As with any magic system, those details are up to you. However, the key artifact of this adjustment is that the mage is committed to a spell, and it will take them work to turn it into something else.
This leaves an opening for the physical fighters. If they can identify what spells are cued up in the wizard, they can simply avoid putting themselves in positions where that spell is effective. This is actually a major part of warfare: your number one priority is making sure the enemy can't shoot you.
You can tune this any number of ways. For example, one approach might be to make it so that spells are weak unless highly specified. You may barely light a candle with a Fireball, but if you memorize a "Fireball pointed north," you can roast a turkey. This, combined with the ability to slowly adjust the spells in your head, will create a rather interesting fight dynamic. The wizard has to keep the spells specific enough to do damage, but the more specific they make them, the easier it is for a physical fighter to avoid them.
This approach also plays well with the idea of rituals which permit wizards to cast extremely powerful spells. If they're willing to take the time to hyper-specialize their spell, it could be extremely strong. However, if a warrior comes up and disturbs the ritual, that power may be very difficult to adjust back into useful fireballs and ice-blasts, so the wizard would be weak during that time.
As always with magic, explore and use creativity, but I think a balance like stated above has great potential.