When we read, the whole chapter in context, we can see that both the blood, and the priestly action, of using the blood of the sacrifice is necessary. Basically, on one point I am agreeing with you....I am just pointing out, that the functions of the priest in the offering was also necessary.
In a nutshell---Jesus is the Second Person of the Trinity, both with totally united two natures, one divine and one human...they can't be separated. This is necessary, to fulfill the requirements of being the Paschal Lamb....if He was just God, in a human shell, it wouldn't have been an acceptable sacrifice for the redemption of mankind, because it would have been a human sacrifice...which is forbidding. However because of the hypostatic union of Jesus's two wills, that took place at the time of Incarnation, He is a perfect sacrifice, for the redemption of mankind.
Hebrews 9
The Old and the New
1Now even the first covenant had (
A)regulations of divine worship and (
B)the earthly sanctuary.
2For there was (
C)a tabernacle prepared, the outer one, in which were (
D)the lampstand and (
E)the table and (
F)the sacred bread; this is called the holy place.
3Behind (
G)the second veil there was a tabernacle which is called the (
H)Holy of Holies,
4having a golden (
I)altar of incense and (
J)the ark of the covenant covered on all sides with gold, in which was (
K)a golden jar holding the manna, and (
L)Aaron's rod which budded, and (
M)the tables of the covenant;
5and above it were the (
N)cherubim of glory (
O)overshadowing the mercy seat; but of these things we cannot now speak in detail.
6Now when these things have been so prepared, the priests (
P)are continually entering the outer tabernacle performing the divine worship,
7but into (
Q)the second, only (
R)the high priest enters (
S)once a year, (
T)not without taking blood, which he (
U)offers for himself and for the (
V)sins of the people committed in ignorance.
8(
W)The Holy Spirit is signifying this, (
X)that the way into the holy place has not yet been disclosed while the outer tabernacle is still standing,
9which is a symbol for the present time. Accordingly (
Y)both gifts and sacrifices are offered which (
Z)cannot make the worshiper perfect in conscience,
10since they relate only to (
AA)food and (
AB)drink and various (
AC)washings, (
AD)regulations for the body imposed until (
AE)a time of reformation.
11But when Christ appeared as a (
AF)high priest of the (
AG)good things [
a]to come, He entered through (
AH)the greater and more perfect tabernacle, (
AI)not made with hands, that is to say, (
AJ)not of this creation;
12and not through (
AK)the blood of goats and calves, but (
AL)through His own blood, He (
AM)entered the holy place (
AN)once for all, having obtained (
AO)eternal redemption.
13For if (
AP)the blood of goats and bulls and (
AQ)the ashes of a heifer sprinkling those who have been defiled sanctify for the cleansing of the flesh,
14how much more will (
AR)the blood of Christ, who through (
AS)the eternal Spirit (
AT)offered Himself without blemish to God, (
AU)cleanse your conscience from (
AV)dead works to serve (
AW)the living God?
15For this reason (
AX)He is the (
AY)mediator of a (
AZ)new covenant, so that, since a death has taken place for the redemption of the transgressions that were committed under the first covenant, those who have been (
BA)called may (
BB)receive the promise of (
BC)the eternal inheritance.
16For where a covenant is, there must of necessity be the death of the one who made it.
17For a covenant is valid only when men are dead, [
b]for it is never in force while the one who made it lives.
18Therefore even the first covenant was not inaugurated without blood.
19For when every commandment had been (
BD)spoken by Moses to all the people according to the Law, (
BE)he took the (
BF)blood of the calves and the goats, with (
BG)water and scarlet wool and hyssop, and sprinkled both (
BH)the book itself and all the people,
20saying, "(
BI)THIS IS THE BLOOD OF THE COVENANT WHICH GOD COMMANDED YOU."
21And in the same way he (
BJ)sprinkled both the tabernacle and all the vessels of the ministry with the blood.
22And according to the Law, one may (
BK)almost say, all things are cleansed with blood, and (
BL)without shedding of blood there is no forgiveness.
23Therefore it was necessary for the (
BM)copies of the things in the heavens to be cleansed with these, but (
BN)the heavenly things themselves with better sacrifices than these.
24For Christ (
BO)did not enter a holy place made with hands, a mere copy of (
BP)the true one, but into (
BQ)heaven itself, now (
BR)to appear in the presence of God for us;
25nor was it that He would offer Himself often, as (
BS)the high priest enters (
BT)the holy place (
BU)year by year with blood that is not his own.
26Otherwise, He would have needed to suffer often since (
BV)the foundation of the world; but now (
BW)once at (
BX)the consummation of the ages He has been (
BY)manifested to put away sin (
BZ)by the sacrifice of Himself.
27And inasmuch as (
CA)it is appointed for men to die once and after this (
CB)comes judgment,
28so Christ also, having been (
CC)offered once to (
CD)bear the sins of many, will appear (
CE)a second time for (
CF)salvation (
CG)without reference to sin, to those who (
CH)eagerly await Him.