What if your 2 longbows and a sword fail to kill the crossbow defender in Marseilles/Bordeaux? Wouldn't the odds be against you in this/these contest(s)?
From the 4-5 trials I've done, it's a 3:1 chance that you'll capture the city with the loss of 1-2 troops (most definitely the swordsman, and probably one of the longbowman). I got lucky one time and captured a city with just the swordsman sacrificed. 1 out of 4 times I lost all 3 but that's OK odds.
BTW, it's important that Bordeaux has Christianity so that its southernmost border has expanded into your territory, so that your settler can declare war. Otherwise on the 3rd move that tile will be nominally Spanish so you won't be able to declare war.
I'm now in 1450, got to liberalism first, chose printing press, already half past conquering Aztecs and Incans, ready to send my first settler to America. Portugal I opened borders with (so that they won't teleport to Porta Delgada), and eventually their settlers died after a plague in Spain. Then they declared war and their troops disappeared somewhere else and into history.
Of course I'm in HR/bureaucracy/pacifism right now.

Built University of Sankore, Forbidden Palace, Leaning Tower and Wat Preah Pisnulok (got beaten to Notre Dame by Netherlands, either France or China for Sistine Chapel and the almighty Spiral Minaret by Mali--of all civs!). France is not doing too bad with just Paris and Rennes, and they know gunpowder and music (which I traded for with paper and philosophy and education), so I'm pretty sure they're researching either astronomy or military tradition. Bilbao and Granada are building citadels/stables and troops while Lisboa is concentrating on ships and money/science. I'm going to switch to Theocracy and Representation soon (8 moves from Constitution and a great engineer to be ready in 7 moves) which I don't think there's a penalty for this combination; and after I conquer the French and Dutch and after Democracy I'll switch to emancipation and free religion.
England is way behind (doesn't even know optics yet), while Germany already has optics. My next move after conquering France will be military science for the frigates to strangle England. Netherlands still only has 1 city so my troops from the French war should crush them like a bug.
Or maybe I should just go for 2/3 UHV (let the English and French found their colonies) and go for a spaceship?