Mixing beta blockers

Hello there .... My question is i'm currently taking metoprolol for migraine headaches and for moderate high blood pressure.... my problem is I was taking a GREAT beta blocker for blood pressure and fast heart rate called Bisoprolol .... it's a great drug for controlling my heart rate and blood pressure but unfortunately it had no affect for my migraines.... Metoprolol works great for my migraines but doesn't have the same affect controlling my heart rate .... is it safe to mix Bisoprolol and metoprolol using spaced out doses...... lets say Bisoprolol in the morning and then metoprolol in the evening .... currently I take 25 mil of metoprolol in the AM and 25 Mil in the evening ..... could I just switch and take the Bisoprolol 2.5 in the am and then 25 metorprolol in the PM ..... This way heart rate controlled and migraines controlled .... metoprolol for some reason does not control my heart rate like Bisoprolol..... thanks so much any advice would be appreciated.....