1. ARE THESE SIDES GENUINE TITLE CONTENDERS?
Both will argue they are but, even this early in the season, doubts have surfaced. As sumptuous as Arsenal are as an attacking force - they were wrongly denied the opening goal by an assistant's flag and Alexis Sanchez also hit the woodwork - they cannot be this open defensively and expect to claim the title.
Likewise, can Liverpool be this profligate and hope to win the league? Philippe Coutinho struck a post and the bar, Christian Benteke was denied from close range and too many chances were spurned.
2. ARSENAL'S BACK-UP DEFENCE RINGS ALARM BELLS
Arsene Wenger would argue only ill luck had cost him his first-choice centre-halves, with Laurent Koscielny nursing a sore back and Per Mertesacker ill.
But the calls for the addition of one more sturdy defender during the window screamed a little louder as the understudies wilted.
Calum Chambers, bullied by Benteke's brutal blend of pace and power, shrank at times while Gabriel Paulista was jittery at the youngster's side.
Hassled and harassed, they were a mess of individual errors whenever Liverpool tore at them.
3. GUNNERS ALSO CRYING OUT FOR MIDFIELD STRENGTH
The centre-halves were not afforded much protection from their midfield, where Francis Coquelin was overworked and, at times, overwhelmed by the brilliance of Coutinho and James Milner's energy.
Coquelin, effectively only a regular for half a season at this level, attempted to break up play and check runners from deep but there were too many gaps for him to plug. Santi Cazorla, a wonderful passer, was no destructive force at the Frenchman's side.
4. LIVERPOOL BOAST EARLY-SEASON BALANCE
The Reds had their own injury problems, the likes of Jordan Henderson and Adam Lallana out of contention. But they had a better balance revolving around Milner's industry, Lucas Leiva's bustle and the creative fulcrum that was Coutinho, particularly in the first half.
The little Brazilian constantly caught the eye and can be their inspiration this season if the unit functions as a whole. It will be interesting to see if Lucas is now retained beyond the transfer deadline.
That this line-up boasted progressive full-backs in Nathaniel Clyne and Joe Gomez, ever eager to provide natural width in an otherwise rather cramped system, bodes well. The ball can be belted upfield to Benteke in the belief it will stick.
5. DESPITE HIS DEBUT BLUNDERS, CECH HAS STILL GOT IT
Any Arsenal fan still dismayed by Cech's errors in that opening weekend defeat at home by West Ham can at least rest a little easier. The goalkeeper's pair of first-half saves defied belief, reminders of the pedigree Wenger prised from Stamford Bridge over the summer and at a snip - £10 million (S$22 million).
Even Cech himself seemed surprised to have thwarted Benteke with that strong left hand from point-blank range as the striker reached Roberto Firmino's low centre. Indeed, Brendan Rodgers was already up and celebrating in the dugout in anticipation of the goal.
The brilliance of that stop actually rather detracted from the subsequent finger-tip save which turned Coutinho's curled attempt on to the far post in stoppage time at the end of the period.