Nausadh, i also have same understanding, like wearing both 4 mukhi and 5 mukhi are beneficial.
Generally one is supposed to wear rudraksha beads in odd numbers, So possibly you can always mix these two beads in such mala.
For your reference to the reason, you can see that saraswati rudraksha mala, contains a combination including 4 mukhi and 5 mukhi. This mala in such a combination is seen to work much better. So no doubt on such combination.
Also the recommendation on wearing rudraksha beads may differ from person to person. If someone is having good knowledge and memory power then possibly 4 mukhi won't be recommended in first advise. But wearing them does not make any issues.
can i wear 4,5,6 mukhi rudraksh at the same time or as combination if yes please suggest me how many beads can i use from each mukhi or can i wear 108+1 mala of all the 3 types at the same time let me also tell you i'm already wearing 5 mukhi mala 108+1 so can i add single bead of 4,6 mukhi to the mala i'm wearing right now the reason as per ma zodiac sign i should wear 4 or 6 mukhi so i'm confused please help me