Fire on both sides
Fire acts before it deliberates, and doubled that becomes the operating principle of the household. Decisions are made fast, quarrels are loud and over quickly, and neither party holds a grudge past the end of the week. Compared with most pairings this is a considerable relief.
What is missing is anything that cools. Neither person is the one who says wait. Money gets spent, jobs get quit and commitments get made in the same afternoon they were conceived, and the consequences arrive later with nobody having planned for them.
Cardinal doubled
Modality is the sharper issue. Cardinal signs initiate, and two initiators produce a great many beginnings and very few completions. Projects accumulate half-built. The house fills with equipment for enthusiasms that lasted a fortnight.
Cardinal also means both parties want to lead, and Aries specifically leads by going first rather than by consulting. Two people going first in different directions is the recurring structural problem of this pairing, and it appears in matters as small as which route to take.
Mars against Mars
Both charts are governed by Mars, so both people fight in the manner their Mars dictates, and the whole relationship is coloured by how those two Mars positions get on.
Two Mars placements in compatible signs produce a pairing that argues hard and recovers fast. Two Mars placements at odds produce something that escalates without either party intending it. This is the single most informative thing to check in an Aries and Aries comparison, and the sun sign gives no indication of it.
Where it grinds
Competition that neither will name. Aries treats most situations as something to win, and applied to a partner that turns ordinary domestic matters into contests over who was right.
Neither party concedes a point easily either, so the contest can run for hours over a matter of no consequence.
The second friction is impatience with weakness, including their own. Neither sign is good at admitting to being tired, frightened or hurt, so both perform being fine. That leaves genuine difficulty unspoken until it comes out as temper.
Same sun, different people
Sharing a sun sign means sharing a default speed. It does not mean sharing needs. One Aries with a Pisces Moon and another with a Virgo Moon want entirely different things from an evening, and the sun says nothing about either.
The sun-sign version of this pairing is a description of a tendency across a very large number of people. Reading the Moon, Venus and Mars for both charts is what makes it a statement about two of them.
Questions people ask about this
Do two Aries fight constantly?
They argue often and briefly. The concern is not frequency but escalation, which depends on how the two Mars placements sit.
What is missing when both partners are Aries?
Patience and follow-through. Neither is the one who waits, so nothing supplies caution and few projects are finished.
Why does Mars matter so much in this pairing?
Because Mars rules both charts. How each person fights and pursues is set by Mars, so its position in each chart shapes everything.
Is a same-sign match better or worse than a mixed one?
Neither. It amplifies one temperament instead of balancing two, which helps in some areas and leaves others uncovered.