let's put it this way, imaging that your income entitles you to maximum of 100k eligible total credit.

if you apply 1 card, the bank gives you 50K CL, that will take away 50K from your 100k.
apply second card, the bank gives you another 40k, you will be left with 10K.
apply third card, the bank may deem you as high risk in debt since your total committed amount is now 90k over 100K.

one shot of multiple cards from different banks may also trigger alert to suspicion. Unless your income is really high and available credit is very high, too.

one shot of multiple cards from different banks may also trigger alert to suspicion. Unless your income is really high and available credit is very high, too.