You are right about this, the market bonus of the Saracens does best in open, aggressive land maps because that is where that is where the strategy is deadliest due to the timing. If they aren’t able to close the game, they can be outlasted by other civs, since they are gold reliant and they also don’t have a permanent eco bonus. The Swahili will have a similar main strategy but with monks instead of archers, which is to smush and to control as much relics as possible. And with the Imp Age UT, they will get more relics to give them an opportunity to outlast the opponent with their gold trickle which could range from 3-4 gold per second, amounting to 180-240 gold a minute which is quite huge. So that is the Swahili’s advantage versus the Saracens, and their game plan to compete and survive in 1v1 land maps.
Also, the Swahilis is designed to be also a great pick in water/hybrid maps and a priority pick in team games, so I think their strength on 1v1 land maps is fine. A civ cannot be too good on 1v1 Arabia, water maps, team games all at the same time, and currently many civs are like that. Given their historical background, my goal really is not make them an S-tier in land maps, rather a B, at least.