I agree with Human Nature on getting both the OCBC and MBB2 Cards for your case.
However I also noted you mentioned you spend up to RM3K and your wife has her own card. Now if your wife has income or pays income tax, then she should also consider getting her own Principal Maybankard 2 Cards or OCBC Titanium MasterCard. This is because with you having the OCBC TMC and MBB2 Card, with RM3K spending you only get back RM100 cash back; but add another principal card from your wife, you can get up to RM150/month cash back.
Say for example, you and your wife's total expenses for Petrol, Groceries, TNB, Telco, Astro, Syabas and eating out is more than RM1K. Then it would be beneficial for your wife to get her own Principal OCBC TMC card too because OCBC Cash Back is capped at RM50/month. You get nothing once you hit the monthly cap.
On the other hand, if your wife shops a lot at places that accept AMEX (like AEON, MJ, Parkson, Mid Valley or 1U), then the Maybankard 2 Cards may be more appropriate as she can earn approximately 2.5% which is better than OCBC TMC 1% cash back. Better still if she spends money on Saturday and Sunday where the MBB AMEX earns her extra 5% cash back.
Click here to read my Maybankard 2 Cards Review where I did a comparison versus
OCBC Titanium MasterCard. Spend RM1K/month with the MBB 2 AMEX and in a year, in additional to earning up to RM600 cash back you will have 60,000 Treats Points to redeem RM300 Parkson cash vouchers.
And to show you how good the Maybankard 2 AMEX is with 5X TP,
click here to read my article FREE Money from Maybankard and Bonus Link for my wife's SK-IIAs for medical bills and car servicing, if they accept AMEX best. But if they don't and you hit the monthly cash back cap with OCBC TMC, then you can either use your HSBC credit card or the Maybankard 2 Cards Visa or MC.
One more thing, I thought HSBC upgrading their cardholders' gold card to platinum. Anyway, if you are happy with HSBC, do consider upgrading to their Visa Signature as you do qualify for it.
Click here to read my article on HSBC Premier World MasterCard and Visa Signature Benefits.
my intention is to keep one card for myself and another sub card for my wife as she going to stop work and be a house wife soon, we kind of thinking re-evaluate our budget to keep into minimal by avoid out of control on swapping card, annual fees waived sound more important to us, cash back and other benefits will be added value, if really go for a single card, which could it be?
I heard some concern about MBB card cancellation issue(one from my brother case as well), they like to drag the cancellation process until the annual fees get impose, and you have to settle it before really cancel